Umm al-Mu'mineen Sayyidah Aisha (may Allah be pleased with her) narrates: The Noble Prophet (peace and blessings be upon him) said: "When a person becomes drowsy during prayer, he should end the prayer, because he does not know—perhaps he thinks he is supplicating for forgiveness, but he is actually cursing himself." (The narrator is in doubt, perhaps these are the words:) "He is praying against himself."