mutta.sil rote hii rahye to bujhe aatish-e dil
ek do aa;Nsuu to aur aag lagaa jaate hai;N

1) if you continually keep on only/emphatically weeping, then the fire of the heart would go out
2) if there are one or two tears, then they increase the fire more as they go



S. R. Faruqi:

mutta.sil = continually, always

Having altered this theme, in our day Muhammad Alvi has well composed,

roz achchhe nahii;N lagte aa;Nsuu
;xa.s mauqo;N pah mazaa dete hai;N

[they don't seem pleasing every day, tears
on special occasions, they give pleasure]

In Mir's verse there's nothing special, but in the second line idiomatic speech has been versified excellently-- especially the wordplay with tears. The observation too is that of everyday life: that when a little water falls on a blazing fire, then because steam rises and a sound is made, one feels that the fire has blazed up more brightly.



I have nothing special to add.