CHAPTER THREE: SADHANA ADHYAYA
Section 4: Aihikadhikaranam: Topic 16 (Sutra 51)

The time of the origination of knowledge when Brahma Vidya is practised.
Aihikamapyaprastutapratibandhe taddarsanat III.4.51 (476)
In this life (the origination of knowledge takes place) if there be no obstruction to it (the means adopted), because it is so seen from the scriptures.
Aihikam: in this life; Api: even; Aprastutapratibandhe: in the absence of an obstruction to it (the means adopted); Taddarsanat: as it is seen in Sruti. (Aprastuta: not being present; Pratibandhe: obstruction; Tat: that; Darsanat: being declared by the scriptures.)
This Sutra states whether the consequence of Brahma Vidya, which is the realisation of Brahman, is possible in this life or will wait till death.
Beginning from Sutra 26 of the present Pada (Section) we have discussed the various means of knowledge.
The question now is whether knowledge that results from these means comes in this life or in the life to come.
The present Sutra declares that knowledge may come in this life only if there is no obstruction to its manifestation from extraneous causes. When the fruition of knowledge is about to take place, it is hindered by the fruit of some other powerful work (Karma), which is also about to mature. When such an obstruction takes place, then knowledge comes in the next life.
That is the reason why the scripture also declares that it is difficult to know the Self, "He of whom many are not even able to hear, whom many even when they hear of him do not comprehend; wonderful is a man when found who is able to teach him; wonderful is he who comprehends him when taught by an able teacher" (Katha Up. I.27).
The Gita also says, "There he recovers the characteristics belonging to his former body, and with that he again strives for perfection, O Joy of the Kurus" (Chap. VI.43). "The Yogin striving with assiduity, purified from sin, gradually gaining perfection, through manifold births, then reaches the Supreme Goal" (Chap. VI.45).
Further scripture relates that Vamadeva already became Brahman in his mother's womb and thus shows that knowledge may spring up in a later form of existence through means procured in a former one; because a child in a womb cannot possibly procure such means in its present state.
It, therefore, is an established conclusion that knowledge originates either in the present or in a future life, in dependence on the evanescence of obstacles.