S. R. Faruqi:

Mir has often used be-tah and tah-daar in the sense of 'convoluted' and 'deep', and in every verse he has created a new pleasure. For example, in the first divan [{585,7}]:

is fan me;N ko))ii be-tah kyaa ho miraa ma((aari.z
avval to mai;N sanad huu;N phir yih mirii zabaa;N hai

[in this art, how would any depth-less person be my competitor?
first, I am a 'warrant'; then, there's this language of mine]

From the fourth divan [{1427,7}]:

jaataa hai kyaa khi;Nchaa kuchh dekh us ko naaz kartaa
aataa nahii;N hame;N ;xvush andaaz-e be-tah-e dil

[look at how she goes strutting around coquettishly
we are not pleased by a style without depth of heart]

In the case of {1427,7}, its rhyme is kare , jale , etc. Among them Mir has also versified be-tah-e dil .

In the present verse, the pleasure is that tah paa))ii nahii;N jaatii can be expressed in other words as be-tah hai;N . But someone's being 'depth-less' and someone's 'depth not being measurable' are not the same thing. This kind of verbal play always creates a particular pleasing tension in the verse.

This theme too is fine, that if if they had been light of heart [dil ke halke] then they would have been full of turbulence and clamor like a flood. The verb josh-o-;xarosh bharnaa seems to be Mir's invention, and it's very fine. It's well known after all that according to how deep water is, on its surface there's proportionately less commotion. Thus in English there's the saying, 'Still waters run deep'. It's an enjoyable verse.

In both lines se is very meaningful. In the first line sail se halke means 'light like a flood'. In the second line daryaa se tah-daar has two meanings: (1) depth-possessing like a river; and (2) more depth-possessing than a river.

The simile too is fine, because no matter how powerful a flood may be, its water is shallower than that of the river in which the flood comes. Then, aave;N too has two meanings: 'to come filling up with ebullience and turmoil; and (2) to fill up with ebullience and turmoil and come (before people).

FWP:

SETS == MIDPOINTS; POETRY; SUBJECT?
MOTIFS
NAMES
TERMS == RHYME; WARRANT

Truly it's a very striking and initially somewhat confusing verse. The first line describes, in the subjunctive, lovers who may be 'light' either 'like' a flood (with se being implicitly short for jaise ) or 'more than' a flood (with se being the comparative), and who thus create a kind of furious turmoil that spreads out widely but shallowly, turbulently but superficially. This 'light' group of lovers seem to be undesirably frivolous or second-rate, as far as we can guess from the first line (see the definition of halkaa above).

Then when we come to the second line-- what's the subject? Presumably 'lovers', but also apparently a different group of lovers, the serious kind-- those who have a 'depth that is not measured/found' (that is, an immeasurable depth), and who are 'deep like a river', and/or 'deeper than a river'. But we have to fiddle with the grammar to make this reading work, for in order to differentiate this group of lovers from the first group we have to create something like a parallel if-then clause structure in the second line (if lovers are light, they are turbulent; if they are deep, they are river-like) even though we have neither an 'if' nor a 'then'.

So we then go back and notice both the double sense (pointed out by SRF) and the 'midpoints' role of tah paa))ii nahii;N jaatii , for if a depth cannot be found, perhaps there's an immeasurable depth, or perhaps there's not much depth there at all. Thus this clause could also apply to the same lovers as in the first line, and could in its unresolvability suggest to us that the verse describes one group of lovers, not two.

For the first line could just as well begin not with a colloquially-omitted 'if', but with a colloquially-omitted 'when'. In that case, the two lines could describe the occasional or superficial or apparent behavior of lovers (in 'light' mode or mood, they foam like a flood), while the second line adds an invisible, underlying truth (they are actually unfathomably deep, like a river/sea). This kind of fast mental footwork, as we reframe the verse on the fly and feel it jerk us around, is just what creates the enjoyable 'tension' of which SRF speaks.

As SRF also observes (and illustrates through {585,7}), Mir's use of tah-daar , though not in this verse explicitly literary, has a latently literary subtext, since Mir often boasts of this quality and related qualities of complexity and subtlety in his verses. For further discussion, see SRF's article on Mir and Ghalib.