CHAPTER FOUR: PHALA ADHYAYA
Section 2: Tadoko'dhikaranam: Topic 9 (Sutra 17)

The soul of the knower of the Saguna Brahman comes to the heart at the time of death and then goes out through the Sushumna Nadi.
Tadoko'grajvalanam tatprakasitadvaro vidyasamarthyattaccheshagatyanusmritiyogaccha hardanugrihitah satadhikaya IV.2.17 (513)
When the soul of a knower of the Saguna Brahman is about to depart from the body, there takes place) a lighting up of the front of its (soul's) abode (viz., the heart); the door (of its egress) being illumined thereby; owing to the power of knowledge and the application of meditation to the way which is part of that (knowledge); the soul favoured by Him in the heart (viz., Brahman) (passes upward) by the one that exceeds a hundred (i.e., the hundred and first Nadi).
Tadoko agrajvalanam: the illumining of the top of its (soul's) abode (the heart); Tatprakasitadvarah: with the passage illumined by this light; Vidyasamarthyat: by the power of his knowledge; Tat seshagatyanusmritiyogat: because of the application of meditation to the way which is part of that knowledge; Cha: and; Hardanugrihitah: being favoured by Him who dwells in the heart; Satadhikaya: by one that exceeds a hundred. (Tat: of that; Okah: abode, the heart; Agrajvalanam: the forepart or the end of the heart being illumined; Tat: by the Lord dwelling in the heart; Prakasita: illumined; Dvarah: door, the root from which the hundred and first Nadi has its origin; Sesha: remainder; Gati: path, the way; Anusmritiyogat: because of the application of the remembrance or constant thought; Harda: the Lord who dwells in the heart; Anugrihitah: being favoured by.)
The discussion about the Para Vidya (Higher Knowledge) is over. The Sutrakara now pursues the discussion of the Apara Vidya, i.e., Upasana (lower knowledge).
It has been already stated in Sutra 7 that up to the beginning of the way the departure of a knower of the Saguna Brahman and an ignorant man is the same. The present Sutra now describes the soul's entering on the way. The Brihadaranyaka text describes the death of a person "He taking with him those elements of light descends into the heart" (Bri. Up. IV.4.1). Then again it says, "The point of his heart becomes lighted up, and by that light the self departs, either through the eye or through the skull or through other places of the body" (Bri. Up. IV.4.2). The soul together with the organs comes to the heart at the time of death.
The question arises whether the departure is the same for a knower of Saguna Brahman and an ordinary man.
The exit of the ordinary man is different from that of the knower of Saguna Brahman. The former goes out from any part of the body at death (eye, ear, nose, anus, etc.). But the latter goes out only through the Sushumna Nadi and out of the Brahmarandhra in the head. If he goes out by any other way he cannot attain the Supreme Abode.
By virtue of knowledge and owing to the application of constant thought of Brahman the point of the heart which is the abode of the departing soul is illumined and through the grace of the supreme soul resident therein, the door of egress, the mouth of the Nadi leading from the heart to the head as stated in Sutra 7 is thrown open. The soul passes into the Nadi numbered one hundred and one. This Nadi is the gateway of the release. The other one hundred Nadis lead to bondage.
The scripture says in a chapter treating of the knower of Brahman dwelling in the heart: "There are a hundred and one Nadis of the heart; one of them penetrates the crown of the head; going up along that one attains Immortality; the others serve for departure in different directions)" (Chh. Up. VIII.6.5).
Although equality for him who does know and him who does not know, the point of the heart becomes shining and the door of egress thereby is lighted up, yet he who knows departs through the skull only, while the others depart from other places. Why so? On account of the power of knowledge. If also he who knows departs like all others, from any place of the body, he would be unable to reach an exalted sphere and then all knowledge would be meaningless.
"And on account of the application of meditation on the way forming a part of that." In different Vidyas there is enjoined meditation on the soul's travelling on the way connected with the Nadi that passes through the skull, which way forms part of those Vidyas. Now it is proper to conclude that he who meditates on that way should after death proceed on it.
Therefore, he who knows being favoured by Brahman dwelling in the heart, on which he had meditated and thus becoming like it in nature departs by the Nadi which passes through the skull which is the hundred and first. The souls of other men pass out by other Nadis.