How does the Prophet Muhammad (peace be upon him) suggest that Fatima and `Ali can alleviate their burden instead of using a servant for household tasks?
 Narrated `Ali:                     Fatima complained of the suffering caused to her by the hand mill. Some Captives were brought to the Prophet, she came to him but did not find him at home `Aisha was present there to whom she told (of her desire for a servant). When the Prophet came, Aisha informed him about Fatima's visit. `Ali added "So the Prophet came to us, while we had gone to our bed I wanted to get up but the Prophet said, "Remain at your place". Then he sat down between us till I found the coolness of his feet on my chest. Then he said, "Shall I teach you a thing which is better than what you have asked me? When you go to bed, say, 'Allahu-Akbar' thirty-four times, and 'Subhan Allah thirty-three times, and 'Al hamdu-li l-lah thirty-three times for that is better for you both than a servant."