शनैः पक्वतया काले प्रसूतं मेचकच्छविम् ।श्वपच्या प्रावृषेवाब्दं श्याममावलितं मलैः
In plain words
slowly, ripening in its time, brought forth by that śvapaca woman as a cloud is brought forth by the monsoon -- dusky of sheen, dark, and smeared all over with filth,