Sahih Bukhari

Narrated `Ali:Fatima complained about the blisters on her hand because of using a mill-stone. She went to ask the Prophet for servant, but she did not find him (at home) and had to inform `Aisha of her need. When he came, `Aisha informed him about it. `Ali added: The Prophet (ﷺ) came to us when we had gone to our beds. When I was going to get up, he said, ""'Stay in your places,"" and sat between us, till I felt the coolness of the feet on my chest. The Prophet (ﷺ) then said, ""Shall I not tell you of a thing which is better for you than a servant? When you (both) go to your beds, say 'Allahu Akbar' thirty-three times, and 'Subhan Allah' thirty-three times, 'Al hamdu 'illah' thirty-three times, for that is better for you than a servant."" Ibn Seereen said, ""Subhan Allah' (is to be said for) thirty-four times