And he said concerning a single garment:

“If it is ample, wrap it around yourself; if it is narrow, wrap it around your waist.”

“He forbade a man to pray in a single garment with none of it covering his shoulder.”

This shows that a man is commanded during prayer to cover his awrah—the thighs and other parts—even if we allow another man to look at them. If, according to one of the two views—which is also one of the two positions reported from Ahmad—we say that the awrah consists of the front and rear private parts and that the thigh is not awrah, this concerns whether another man may look at it; it does not concern prayer or circumambulation. A man may not pray with his thighs uncovered, whether or not they are considered awrah, nor may he circumambulate naked. Rather, he must pray wearing a garment; this is indispensable. If it is narrow, he wraps it around his waist, and if it is ample, he wraps it around himself. Likewise, even if he prays alone in a house, he must cover those parts, by scholarly consensus.

As for a man praying with his thighs exposed when he is able to wear a waist-wrapper, this is impermissible, and there should be no disagreement about it. Those who have based this question on the two positions reported concerning the awrah, as some have done, are mistaken. Neither Ahmad nor anyone else said that a worshipper may pray in this state. How could that be, when Ahmad commands him to cover his shoulders? How, then, could he permit him to uncover his thigh? That, then, is the point.