ya((nii : 'That is to say, viz., i.e., to wit, videlicet; — for, because'. (Platts p.1250)
mihrbaan : 'Loving, affectionate, friendly, kind, benevolent, beneficent, favouring, indulgent, gracious, propitious; compassionate, merciful'. (Platts p.1100)
qaabil : 'Approaching, ensuing, following; next (year); a recipient; capable, able, skilful, clever; worthy, sufficient'. (Steingass p. 946)
The Lord is kinder than a father. In search of a livelihood, we wandered from door to door. This is only/emphatically our incapacity. Perhaps if we had stayed at home in pious trust, then he would have given us the needful.
For more on Ghalib's unpublished verses, see the discussion in {4,8x}. See also the overview index.
Zamin was so hostile to that ya((nii in the first line that I gave it some close attention, and I think it's there for a reason. Under oral performance conditions, we would initially hear ;xudaa yaa , and we would only be able to correct ourselves retrospectively. For ;xudaa yaa is a fine Ghalibian exclamation; here are some examples: {117,6x}; {120,2}; {205,2}; {225,4x}. In all except {120,2}, it even occurs right at the beginning of the line, just as it briefly seems to do in the present verse. And in a verse so equivocal about calling on the Lord, a sort of halfway call is the perfect thing.
There's also the wordplay of qaabil as 'approaching, following' (see the definition above), so that naa-qaabilii would also mean 'non-approachingness'; this is of course a secondary sense (since it's usually temporal), but it adds to the pleasure of a verse about random wandering and avoidance.
Zamin:
That is, it was our unworthiness, that we left off trusting the Lord and took up wandering from door to door. In the first line, ya((nii is entirely inappropriate, and the omission of the verb is far from a proper taste. If instead of ya((nii there were ;hub hai , then the verse would have been clear and the claim would have been proved.
== Zamin, p. 402