9.1  Te, to you; anasuyave, who are not given to cavilling, who are free from carping; pravaksyami, I shall speak of; idam, this.
The Lord uttered the word 'this' by bearing in mind as an immediately present fact the knowledge of Brahman that will be and was spoken of in the earlier chapters. The word tu (however) is used for pointing out a distinction [The distinction of Knowledge from meditation that was being discussed.].
(I shall speak) of this itself-what is that?-(it is) guhyatamam, the highest secret; and is jnanam, Knowledge, complete Knowledge-nothing else-, the direct means to Liberation, as stated in the Upanisads and the Smrtis, 'Vasudeva is all' (7.19), 'the Self verily is all this' (Ch. 7.25.2), 'One only, without a second' (op. cit. 6.2.1), etc., and also as stated in such Upanisadic texts as, 'On the other hand, those who understand otherwise than this come under a different ruler, and belong to the worlds that are subject to decay' (op. cit. 7.25.2). (Knowledge) of what kind? It is vijnana-sahitam, combined with experience; jnatva, by realizing, by attaining; yat, which Knowledge; moksyase, you shall be free; asubhat, from evil, from worldly bondage.