Verses 3 and 4 as per Sankara Bhashya with commentary by Shri Alladi Mahadeva Sastri
ye tv aksaram anirdesyam avyaktam paryupasate
sarvatra-gam acintyam ca kuta-stham acalam dhruvam (12.03)
sanniyamyendriya-gramam sarvatra sama-buddhayah
te prapnuvanti mam eva sarva-bhuta-hite ratah (12.04)
The Worshippers of Akshara Imperishable
Are not the others then the best Yogins?—— Stop; hear thou what I have to say regarding them.
Because the Imperishable (Akshara) is unmanifest, He is not accessible to words and cannot therefore be defined. He is unmanifest,not manifest to any of the organs of knowledge. They contemplate the Imperishable everywhere all around. Contemplation (Upasana) consists in approaching the object of worship by way of meditating on it according to the teaching (sastra) and dwelling for a long time steadily in the current of the same though – continuous – like a thread of descending oil. The Imperishable who is the object of contemplation is thus qualified. He is omnipresent all-pervading like the Akasa. He is unthinkable because He is unmanifest. Whatever is visible to the senses can be thought of by the mind also; but the Akshara is invisible to the senses and therefore Unthinkable. He is Unchangeable kutastha —– kuta means a thing which good to all appearance but evil within. Accordingly it refers here to the seed of samsara including avidya nescience and other things, which is full of evil within designated by various terms such as Maya, Avyakrita (undifferentiated) as in Svetasvataropanishad (4.10) and in the Gita (7.14), Kutastha means He who is seated in Maya as its witness, as its Lord. Or Kutastha may mean remaining like a heap.Hence He is immutable and eternal. They who contemplate the Imperishable, curbing all their senses and always equanimous whether they come by the desirable or the undesirable, they come to Myself. It needs no saying they come to ME. For it has been said that ‘the wise man is deemed by my very self’ (7.18) Neither is it necessary to say they are the best Yogins, seeing that they are one with the Lord Himself.