S. R. Faruqi:

lagnaa = to be equal, to be comparable

'To ride on a horse of wind/air' [baa))o ke gho;Re par savaar honaa] means 'to show an extreme amount of arrogance'. Bringing to bear his own special style of cleverness/trickery, Mir has versified an idiom of idioms, and he has not let its dictionary meaning slip through his fingers either. The horse of the lifetime/age is so fast-moving that even a horse of wind (that is, the wind, which is swift-moving like a horse) cannot compare with it.

Arrogant people are called 'riders on a horse of wind' because they swiftly pass by, and also because ordinary people cannot obtain access to them. But the horse of the lifetime/age is fast-moving to such an extent that evena horse of wind-- that is, the speed of arrogant people-- cannot compare with it.

The word lage is also a zila with the word baa))o . Then, in the construction samand-e ((umr there's a grandeur, and on baa))o kaa gho;Raa there's a hominess. As though the superiority of the horse of lifetime/age over the horse of wind is manifest even in this way.

FWP:

SETS == IDIOMS
MOTIFS
NAMES
TERMS == IHAM; ZILA

The zila to which SRF refers, baa))o lagnaa , 'for the wind to begin to blow', is a bit of an iham as well, because it could misdirect the hearer of the second line into thinking that the line was about the blowing of the wind; not until hearing the very last word of the line could the listener realize the nature of the error.

How can I possibly refrain from linking this verse to Ghalib's version of the same theme:

G{98,4}

As so often, the best way to appreciate the brilliance of both poets' verses is to compare them to each other, and then to try to find words for what each one achieves.