S. R. Faruqi:

vājib = a thing without which something else cannot exist
mumkin = a thing the existence of which depends on something else
maṣdar = a place of beginning, a place to which return would be made

In the first line the construction has turned out to be very awkward. But the line is so flowing, and the tone so confident, that the attention isn't drawn toward the construction. When we set out to turn it into prose, then it's difficult, because it's not clear why there are two kā 's in the line. In any case, the prose will be like this: maṣdar-ṣifat (that is, like a maṣdar ) ṡanā kā , (that is,) vājib kā mumkin nahīñ ho saktā . That is, we cannot change the necessary into the contingent.

The idea is that just as the maṣdar of all substances (that is, their origin, the place to which they all have to return-- that is, the place beyond which there's nothing-- that is, the Lord) is necessary, in the same way praise of the maṣdar (that is, praise of the Lord) too is necessary (that is, necessary in its own essence, not dependent for its existence on any other thing). And when that is necessary, then we cannot express it by means of words (which are only contingent, because their existence is dependent on something else).

The simple meaning is that praise of the Lord is impossible/noncontingent [nā-mumkin]. The interpretation of vājib kā mumkin nah ho is that vājib kā mumkin nahīñ ho saktā . Here kā has been used in an extremely fine way. For example, they say ādhe kā pūrā nahīñ ho saktā ; that is, the thing that is half cannot become whole.

In the second line he has said that if the name of the Lord comes to our lips, then this too is through the power of the Lord. That is, without the power of the Lord this is not possible. If the Lord would not so wish, or the Lord would not exert his power, then what capacity does mankind have to invoke His name? The meaning of lab par nām ānā can also be, as well as 'to mention', 'to remember'. Now the interpretation emerges that if we remember the Lord, then this is His power.

For ḳhudā kī qudrat there are three meanings. One is the one that has been mentioned above, that this is an expression of the Lord's power. Reference has also been made to the second meaning, that if the Lord so wills, only then can we bring his name to our lips. The third meaning is exclamatory, that if his name comes upon our lips, then that is his power. That is, that if even deaf-mutes like us, or even sinners like us, remember him and mention him, then if this isn't the power of the Lord, then what is it?

Moreover, in the whole line is hidden the meaning that if the Lord's name comes to our lips only through the will of the Lord himself, then if we don't remember him, what sin do we commit? To encompass so many meanings within a verse of praise [ḥamd] is a difficult task fit for Mir alone. On the basis of its fineness of meaning, the troublesome entanglement of the first line (or rather its weakness of poetic structure [naz̤m], which is very rare in Mir) becomes acceptable.

Nasikh has inverted Mir's theme and expressed it in a very spectacular way:

yāñ kuchh asbāb ke ham bande hī muḥtāj nahīñ
nah zabāñ ho to kahāñ nām-e ḳhudā paidā ho

[here, only/emphatically we slaves are not lacking in any resources--
if we would have no tongue, then how would the Lord's name be brought forth?]

The truth is that the verse is good, but it doesn't have a subtlety like that of Mir's verse.

[See {217,3}.]

FWP:

SETS
MOTIFS
NAMES == LORD
TERMS

What a monstrous first line! It's really tortuous, grammatically speaking. It's true that the words flow along so elegantly, rhythmically, even smugly-- you feel that the awkwardness must be your own fault. But this time, it's not. Here's my best attempt at explication, based mostly on SRF's reading:

vājib kā ho nah mumkin = Of/from the necessary, the contingent would not [come to] be [that is, something necessary would not become something merely possible or 'contingent'; it would always remain necessary].

ṡanā kā maṣdar ṣifat = Like the source/origin/ground of praise. (The ṣifat has to apply to the whole phrase ṣanā kā maṣdar , because otherwise the kā is left dangling.)

The first half of the first line is in fact doubly confusing because the normal, least-marked meaning of mumkin is not 'contingent' (in a philosophical sense) but 'possible', in a plain everyday sense, so that nah mumkin readily suggests nā-mumkin , 'impossible'. The reader's mind plays with ways that some necessary thing might prove also to be impossible, a (Ghalib-like) paradox so enjoyable that it's hard to let go of it. But that kā forces the expression to become, 'to make of the necessary, the contingent' and thus denies us the chance to read 'the necessary would not be possible'.

As SRF observes, the verse locates all power in the Lord: if we can't praise him without his willing it so, then how are we at fault if we don't praise him? That's an enjoyable little twist of the otherwise mainly clunky rhetorical/theological content. But I don't find that enough. As far as I'm concerned, SRF could well have omitted this verse from SSA. That first line is like a chunk of gristle, your mind can chew and chew on it but it never repays the effort.