muttaṣil rote hī rahye to bujhe ātish-e dil
ek do āñsū to aur āg lagā jāte haiñ
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
[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.
