mujh ko vuh do kih jise khā ke nah pānī māñgūñ
zahr kuchh aur sahī āb-e baqā aur sahī
1) give me that, after drinking/'eating' which I would not ask for water
2) poison is something more/different, no doubt; the 'water of eternity' is another/other, indeed
aur : 'And, also, for the rest, besides, again, moreover; but, yet, still; over, else; and lo!; — another, other, different; more, additional'. (Platts p.104)
baqā : 'Remaining; duration, permanence; eternity; immortality'. (Platts p.159)
For more on Ghalib's unpublished verses, see the discussion in {4,8x}. See also the overview index.
This ghazal is extremely late (1865) and has received very little commentarial attention.
On the idiomatic range of sahī expressions, see {9,4}. This verse makes a double use of the expression.
For more on the 'water of eternity', see {49,6}.
Gyan Chand is very sure that only poison can meet the criterion imposed in the first line, but I don't see why. Surely it's quite possible that someone who had once drunk the 'water of eternity' would never ask for ordinary water again? After all, Khizr is the only possible case study, and we really have no idea whether he eats and drinks in the ordinary way.
The real pleasure of the verse is in fact the brilliant uncertainty of the second line. Do those two occurrences of aur refer to something 'more, additional', or to something 'other, different' (see the definition above)? (The colloquial vigor always makes me think of a more limited English counterpart: 'It's really something else!')
And then-- the tone! As the speaker sets up the two possibilities, immediate death versus eternal life, is he bitter, or teasing, or sarcastic, or meditative?
Gyan Chand:
Granted that poison is one/another thing and the 'water of life' [āb-e ḥayāt] another-- that is, poison is not the 'water of life'-- still, give me something such that having drunk/'eaten' it, no desire/search for anything would remain. I wouldn't even ask for water. It's obvious that only poison can be such a thing; the 'water of life' cannot. Having drunk a deadly [halāhal] poison, one will immediately be finished off. No need of any further thing will remain.
== Gyan Chand, p. 521