A man who prays in a place that is not clean

Ibn Tawus said: If my father was in a place that was not clean and the time of prayer came, he would have a mat brought and spread out, and he would pray on it.

Uthman bin al-Aswad said: Mujahid once saw me sprinkling water on the place on the roof where we prayed. He said to me: "Do not sprinkle water here, for that will only add to the dirt. Rather, blow on the place where you are going to prostrate, to clean it."