Abu Dawood: Hadith 5064

Fatimah complained to the Prophet (ﷺ) of the effect of the grinding stone on her hand. Then some slaves (prisoners of war) were brought to him. So she went to him to ask for (one of) them, but she did not find him. She mentioned the matter to "A'ishah. When the prophet (ﷺ) came, she informed him. He (the prophet) visited us (Ali) when we had gone to bed, and when we were about to get up, he said: stay where you are. He then came and sat down between us (her and me), and I felt the coldness of his feet on my chest. He then said; "Let me guide to something better than what you have asked. When you go bed, say: Glory be to Allah" thirty-three times." Praise be to Allah" thirty-three times, and " Allah is most Great" thirty-four times. That will be better for you than a servant.