There is an interesting story behind this knowledge. It is a very secret knowledge which cannot be imparted to all people. And Indra got this knowledge from Sage Dadhyaṅṅ. Greedy that he was, he did not want others to know this. He wanted to have this knowledge only for himself. He had told his Guru, "If you tell this to anybody else, I will cut off your head." He was a very strange disciple, and the Guru said nothing. He kept quiet. Indra desired to be the only knower of it. Such a great secret it is! Then two other gods known as the Aśvinis - they are the twin celestial physicians - wanted to have this knowledge. They knew that this Guru knows this - the Madhu-Vidyā. So they came and said: "Will you teach us Madhu-Vidyā?" The Guru Dadhyaṅṅ Ātharvaṇa Rishi said: "You know the danger behind my telling what I know? I will lose my head." "Why?" they asked. He told them: "This is what happened. That foolish Indra, I taught him something, and this threat is the gratitude he gave me. He says, if I tell this to anybody else, he will sever my head. So, if I tell you, my head will go." "Oh, you do not bother about it," the twins said, "We shall look to it. We shall take care of this matter. You do not be afraid of losing your head." "How are you going to save me?" "You start teaching. Then, we cut off your head. Then, we will bring the head of a horse and place it on the trunk of your body, and you speak through the horse's mouth. Then Indra will get angry and cut off your head. But what he will cut off is the horse's head only. Afterwards he will go away and we will replace your real head and join it so that you become all right. Thereby you will not have lost anything." That was a very good idea. Then Sage Dadhyaṅṅ began to speak and the Aśvinis cut off his head and kept it safe somewhere, in secret. They brought the head of a horse from somewhere, fixed it on the sage's trunk and gave it life. Immediately the horse started speaking the Madhu-Vidyā, and through the mouth of the horse it is that this wisdom has come. Indra got enraged on seeing that the sage had started imparting the Madhu-Vidyā. He went and cut off that head he found on the sage's neck - the horse's head. Then the Aśvinis came and put back the original head on the sage and made him whole again.

So, this is the interesting story behind the Vidyā called Madhu-Vidyā. But whatever the story is behind this enunciation of the Vidyā, it is a magnificent statement of the Upaniṣhad, where it tells us that everything is organically related to everything. When you touch anything, you are touching everything. If I touch a table, I am touching the sun at once. Nobody can understand the mystery behind this thing. Everything is vitally connected, not merely artificially related, so that when I see anything, I am seeing everything. When I speak to anyone, I am speaking to everybody. When I touch anything, I touch all things, and when I know one thing, I know everything. This point is really a magnificent theme in the Bṛhadāraṇyaka Upaniṣhad. No wonder Indra was very fond of it and did not want others to know it.

1. iyam pṛthivī sarveṣᾱṁ bhῡtᾱnᾱm madhu, asyai pṛthivyai sarvᾱṇi bhῡtᾱni madhu; yaś cᾱyam asyᾱm pṛthivyᾱṁ tejomayo'mṛtamayaḥ puruṣaḥ, yas cᾱyam adhyᾱtmaṁ śᾱrīras tejomayo'mṛtamayaḥ puruṣaḥ, ayam eva sa yo'yam ᾱtmᾱ, idam amṛtam, idam brahma, idaṁ sarvam.

Iyam pṛthivī sarveṣᾱṁ bhῡtᾱnᾱm madhu: So, do not cut off my head because I am telling it to you. This earth is the honey of all beings. It is the essence and milk of all beings. People suck this earth as if they suck honey which has such a beautiful taste; and earth sucks everybody and everything as if they are honey to it. The earth is the honey of all, and everyone is the honey of the earth. The earth is absorbed into the 'being' of everything, and everything is absorbed into the 'being' of the earth. That is the meaning of saying that earth is the honey of all beings, and all beings are the honey of the earth. It is the honey that you absorb into your being by sucking, by licking, by enjoying, by making it a part of your own 'being'. So does the earth make everything a part of its own 'being' by absorbing everything into itself. And so does every 'being' in the world suck the earth into itself and make it a part of its own 'being'.

Asyai pṛthivyai sarvᾱṇi bhῡtᾱni madhu; yaś cᾱyam asyᾱm pṛthivyᾱṁ tejomayo'mṛtamayaḥ puruṣaḥ, yas cᾱyam adhyᾱtmaṁ śᾱrīras tejomayo'mṛtamayaḥ puruṣaḥ:  Apart from the earth and the beings who are correlated in this manner, there is another superior principle present in the earth and in all beings. That superior principle is the luminous consciousness. There is an animating being behind this physical entity that you call the earth, and an animating principle behind what you call all the beings, creatures, individuals, in the world. That which is cosmically animating all creation and that which is individually animating every little creature, that also has to be taken into consideration in the correlationship of the objective and the subjective aspect of creation. The earth that is mentioned here is not merely this little ball of mud on which we are sitting. It is the entire physical creation. The whole physical creation is what is designated as 'earth'. And here there is a description of the correlativity and correlationship which are animated by the same consciousness. There is an immanence of consciousness in the objective universe and an immanence of consciousness in the individual beings, manifesting in some degree, not always in the same degree. Now, these two are correlated. Just as the objective world and the subjective individual are organically connected, so is this animating consciousness in the objective world correlated with the individual consciousness. One is hanging on the other, one is connected with the other, one is dependent on the other, one is incapable of being without the other. That Being which animates the cosmic and the individual aspects of creation is called the Luminous Immortal Being - tejomayo' mritamayah purusah. He is called the Puruṣha because the Puruṣha is etymologically that which exists in anybody, or that which animates anybody. It may be an individual body or a Universal Body. In either case it is known as the Puruṣha. It may be the Puruṣha that is individual when we merely call it the Puruṣha, otherwise we call it Puruṣhottama - yaś cᾱyam ᾱsv apsu tejomayo'mṛtamayaḥ puruṣaḥ.

Ayaṁ eva sa yo'yam ᾱtmᾱ: That is this; this is that; there is no distinction between the two. The individual is not constitutionally separate from the substance of the whole, and the whole is not in any way different from the structure of the part. They are essentially the same. That which connects the part with the whole and the whole with the part is what is called Puruṣha. The Being that is between the two as a need, as it were, is the immortal essence of the cosmos as well as the individual - sa yo'yam ᾱtmᾱ. This is the Ātman that we speak of. This is the Self of the Universal Being; this is the Self of the individual being; this is the Self of what is outside; this is the Self of what is inside. This is all - idaṁ sarvam. This is called Brahman, the Absolute. It is filling all space, existing everywhere, filling all things. It is a plenum; it is fullness; and therefore it is called Brahma. The word Brahma comes from the root Brahm, to fill everything, complete everything, and to be self-sufficient in every respect. That which is overwhelming and complete in itself is Brahma, and that is the Ātman or the Self of all beings - idam brahma, idaṁ sarvam.

This earth element is of this nature. So are all other elements capable of being correlated in this manner. The objective principles are present in the individual bodies in some form. The physical body is an individual projection of the cosmic physical substance. The physical solidity that we feel in the body of ours, actually and substantially, is the earth element. It is the earth that appears solid, and there is nothing in this body of ours which is not of the earth. Likewise, the water principle is present in us; fire principle is present in us; the air principle and all other principles are present which are mentioned one by one, gradually.

2. imᾱ ᾱpaḥ sarveṣᾱṁ bhῡtᾱnᾱm madhu, ᾱsᾱm apᾱṁ sarvᾱṇi bhῡtᾱni madhu, yaś cᾱyam ᾱsv apsu tejomayo'mṛtamayaḥ puruṣaḥ, yaś cᾱyam adhyᾱtmaṁ raitasas tejomayo' mṛtamayaḥ puruṣaḥa; ayam eva sa yo'yam ᾱtmᾱ; idam amṛtam, idam brahma, idaṁ sarvam.

Imᾱ ᾱpaḥ sarveṣᾱṁ bhῡtᾱnᾱm madhu, ᾱsᾱm apᾱṁ sarvᾱṇi bhῡtᾱni madhu: The water principle is the honey of all beings, and all beings are the honey of the water principle as the cause thereof, and the cause which is the water principle is not independent of the part which proceeds from the whole. Āsᾱm apᾱṁ sarvᾱṇi bhῡtᾱni madhu, yaś cᾱyam: Up to that which is animating the water principle and that which is animating the parts thereof, that is the immortal Being. Tejomayo'mṛtamayaḥ puruṣaḥ, yaś cᾱyam adhyᾱtmaṁ raitasas: The seed in the individual, the vital force in the individual is the representation of the water principle in the cosmos. Both these are correlated to each other, and they are animated by a single Being, the Immortal Ātman, the Self of all which is, veritably, everything, the Absolute Brahman.

3. ayaṁ agniḥ, sarveṣᾱṁ bhῡtᾱnᾱm madhu; asyᾱgneḥ sarvᾱṇi bhῡtᾱni madhu; yaś cᾱyam asminn agnau tejomayo'mṛtamayaḥ puruṣaḥ, yaś cᾱyam adhyᾱtmaṁ vᾱṅ-mayas tejomayo'mṛtamayaḥ puruṣaḥ, ayam eva sa yo'yam ᾱtmᾱ, idam amṛtam, idam brahma, idaṁ sarvam.

Ayaṁ agniḥ, sarveṣᾱṁ bhῡtᾱnᾱm madhu: This fire principle is the honey of all beings, and everything that is a part thereof is naturally included in the whole. I need not mention it once again. Asyᾱgneḥ sarvᾱṇi bhῡtᾱni madhu; yaś cᾱyam asminn agnau tejomayo'mṛtamayaḥ puruṣaḥ, yaś cᾱyam adhyᾱtmaṁ vᾱṅ-mayas tejomayo'mṛtamayaḥ puruṣaḥ, ayam eva sa yo'yam ᾱtmᾱ, idam amṛtam, idam brahma, idaṁ sarvam: This fire principle is manifest in the speech of the individual. The speech is an action, an activity which is superintended by the fire principle. If there is no fire in the system, you cannot speak. So, these are correlated with each other as part and whole, cause and effect. But this causal relationship between fire and the speech principle is made possible by the presence of the immanence of the Cosmic Being who is the Puruṣha Supreme - tejomayo'mṛtamayaḥ puruṣaḥ.

4. ayaṁ vᾱyuḥ sarveṣᾱṁ bhῡtᾱnᾱm madhu; asya vᾱyoḥ sarvᾱṇi bhῡtᾱni madhu; yaś cᾱyam asmin vᾱyau tejomayao'mṛtamayaḥ puruṣaḥ, yaś ᾱyam adhyᾱtmam prᾱṇas tejomayo'mṛtamayaḥ puruṣaḥ, ayaṁ eva sa yo'yam ᾱtmᾱ, idam amṛtam, idaṁ brahma, idaṁ sarvam.

This air is of the same nature. The breath that you breathe, the vital energy in us, that is the correlate in the individual aspects of the cosmic Hiraṇyagarbha, Prāṇa and Vāyu, and they are correlated, so that when the part is conceived, the whole is automatically conceived. The Upaniṣhad will take pains to make clear the point that this co-relationship is not mechanical or artificial, but vital, living and organic. To bring out this point it is that the Puruṣha is brought in as the connecting principle. Consciousness is equally present in the cause as well as the effect. It is in the outside world and also in the inner individual. So, when any particular function of the individual is taken into consideration for the purpose of effecting or producing anything, the cause has to be taken into consideration at the same time. If the cause is forgotten and the individual alone is emphasised in a particular action, it would be the source of bondage. The bondage of the individual is due to the emphasis of the individual independently of the cause which is organically connected by the very same Ātman that is present in both. So, the essence of the Madhu-Vidyā is the cosmic contemplation of Reality. Prāṇa within and Vāyu outside, they are both correlated and connected by a single immortal essence.

5. ayaṁ ᾱdityaḥ sarveṣᾱm bhῡtᾱnᾱm madhu; asyᾱdityasya sarvᾱṇi bhῡtᾱni madhu; yaś cᾱyam asminn ᾱditye tejomayo'mṛtamayaḥ puruṣaḥ, yaś cᾱyam adhyᾱtmaṁ cᾱkṣuṣas tejomayo'mṛtamayaḥ puruṣaḥ, ayam eva sa yo'yam ᾱtmᾱ, idam amṛtam, idam brahma, idaṁ sarvam.

Ayaṁ vᾱyuḥ sarveṣᾱṁ bhῡtᾱnᾱm madhu: Now, the sun is connected with the eye. We are able to see things on account of the principle of the sun that is present in our eyes and the connecting link between the sun and the eyes in again the same Puruṣha. Wherever you see the connecting link between the macrocosmic and the microcosmic you find the same Puruṣha. So, the one Being is the active, energising Reality of any aspect of the cosmos as well as the corresponding aspect of the individual. So, here the sun and the eye are correlated.

6. imᾱ disaḥ sarveṣᾱm bhῡtᾱnᾱm madhu; ᾱsᾱṁ diśᾱṁ sarvᾱṇi bhῡtᾱni madhu; yaś cᾱyam ᾱsu dikṣu tejomayo'mṛtamayaḥ puruṣaḥ, yaś cᾱyam adhyᾱtmaṁ śrotraḥ prᾱtiśrutkas tejomayo'mṛtamayaḥ puruṣaḥ, ayam eva sa yo'yam ᾱtmᾱ, idam amṛtam, idam brahma, idaṁ sarvam.
   
   
7. ayaṁ candraḥ sarveṣᾱm bhῡtᾱnᾱm madhu; asya candrasya sarvᾱṇi bhῡtᾱni madhu; yaś cᾱyam asmiṁs candre tejomayo'mṛtamayaḥ puruṣaḥ, yaś cᾱyam adhyᾱtmam manasas tejomayo'mṛtamayaḥ puruṣaḥ, ayam eva sa yo'yam ᾱtmᾱ, idam amṛtam, idam brahma, idaṁ sarvam.
   
   
8. iyam vidyut sarveṣᾱm bhῡtᾱnᾱm madhu; asyai vidyutaḥ sarvᾱṇi bhῡtᾱni madhu; yaś cᾱyam asyᾱṁ vidyuti tejomayo'mṛtamayaḥ puruṣaḥ, yaś cᾱyam adhyᾱtmaṁ taijasas tejomayo'mṛtamayaḥ puruṣaḥ, ayam eva sa yo'yam  ᾱtmᾱ, idam amṛtam, idam brahma, idaṁ sarvam.
   
   
9. ayam stanayitnuḥ sarveṣᾱm bhῡtᾱnᾱm madhu; asya stanayitnoḥ sarvᾱṇi bhῡtᾱni madhu; yaś cᾱyam asmin stanayitnau tejomayo'mṛtamayaḥ puruṣaḥ, yaś cᾱyam adhyᾱtmaṁ śᾱbdaḥ sauvaras tejomayo'mṛtamayaḥ puruṣaḥ, ayam eva sa yo'yam ᾱtmᾱ, idam amṛtam, idam brahma, idaṁ sarvam.
   
   
10. ayam ᾱkᾱśaḥ sarveṣᾱm bhῡtᾱnᾱm madhu; asyᾱkᾱśasya sarvᾱṇi bhῡtᾱni madhu; yaś cᾱyam asminn ᾱkᾱśe tejomayo'mṛtamayaḥ, puruṣaḥ, yaś cᾱyam adhyᾱtmam hrdyᾱkᾱṣaḥ tejomayo'mṛtamayaḥ puruṣaḥ, ayam eva sa yo'yam ᾱtmᾱ, idam amṛtam, idam brahma, idaṁ sarvam.

Likewise, the quarters of the heavens and the ears are correlated. The mind and the moon are correlated, and the Upaniṣhad goes on to correlate the light that is flashed forth by the lightning above and the light that is projected by the body by its own energy. The sounds that are made outside in the world are also causally connected with the effect as the sounds made in our own bodies by various functions. The space that is outside is not independent of the space in our own bodies. It is the same space that is operating inside also. The space in the heart within is the space that is outside. Both are internally connected.