aur to rakhne ko ham dahr me;N kyaa rakhte the
faqa:t ik shi((r me;N andaaz-e rasaa rakhte the
1) what more/else in the world/age, to preserve/cherish, did we used to have/keep?
2) only a single/particular/unique/excellent penetrating/'attaining' style in verse, we used to have/keep
rakhnaa : 'To protect, preserve, keep, take care of, save; to keep, maintain; to keep, put, place, lay (upon or before), set, station, deposit, lay down, pledge, stake; to keep back, reserve; to put by, put aside; to leave; to stop; to possess, own; to have, hold, harbour, entertain; to deem, esteem, consider; to engage, employ, take into service'. (Platts p.597)
ek : 'One, single, sole, alone, only, a, an; the same, identical; only one; a certain one; single of its kind, unique, singular, preëminent, excellent'. (Platts p.114)
rasaa : 'Arriving, attaining; causing to arrive (used as last member of compounds); quick of apprehension, acute, sharp, penetrating, skilful, capable, clever; — mixing or mingling (with); amiable; well-received, welcome'. (Platts p.591)
FWP:
SETS == EK; POETRY
For background see S. R. Faruqi's choices. This verse is NOT one of his choices; I thought it was interesting and have added it myself. For more on Ghalib's unpublished verses, see the discussion in {4,8x}.
This verse and the next one form a kind of small unofficial verse-set. This one could quite well stand alone, but the next one, {150,3x}, definitely could not.
Could there ever be a cleverer use of ik ? A tiny little monosyllable in the second line, even further shortened (for metrical convenience) from ek . It might look modest, even humble. Yet what a fine range of meanings-- including 'single of its kind, unique, singular, preëminent, excellent' (see the definition above).
The second line also describes Ghalib's style as rasaa , which has the basic sense of 'arriving, attaining, getting access' (see the definition above). Thus the verse combines a modest-sounding first line with a matter-of-fact statement of quite lofty self-praise in the second line. But remember, this verse is designed to segue into {150,3x}-- which will alter the mood considerably.