The mosque is regarded as a sacred place and is held in high esteem by the Muslims. The Prophet (blessings and peace of Allah be upon him) taught us what is and is not permissible in the mosque. In this hadith, Sahl ibn Sa‘d (may Allah be pleased with him) narrates that the Prophet (blessings and peace of Allah be upon him) came to the house of his daughter Fatimah (may Allah be pleased with her) one day, to check on his daughter and see how she was getting on with her husband. He did not find ‘Ali in the house, and that was at a time when the men would usually be at home. So he asked her: Where is your cousin? He did not say, Where is your husband, or your father’s cousin, so as to soften her heart by reminding her of the ties of kinship between them. She told him that something had happened between them, and they had had an argument that led to both of them becoming angry, so he had left, because he wanted to put a stop to the argument, and because going out and keeping away would allow the flames of anger to die down. Hence he did not spend the time of the siesta with her at home. The siesta is a nap that is taken at midday or in the afternoon. The Prophet (blessings and peace of Allah be upon him) instructed one of his companions to look for ‘Ali and find out where he was, and he found him in the mosque. So the Messenger of Allah (blessings and peace of Allah be upon him) came and found ‘Ali asleep, laying on his side in the mosque. His garment had fallen from his side, and dust had gotten onto him. The Messenger of Allah (blessings and peace of Allah be upon him) began to wipe the dust from him with his hand, saying: Get up, Abu Turab; get up, Abu Turab. Abu Turab (lit. Father of Dust) was a kunyah that the Prophet (blessings and peace of Allah be upon him) gave to ‘Ali (may Allah be pleased with him) because he was sleeping on the dust and it had gotten onto his clothes and body. By doing that, he showed kindness to him and calmed his anger; it comforted him whilst carrying an implicit and gentle rebuke, because the Prophet (blessings and peace of Allah be upon him) did not rebuke ‘Ali for being angry with his wife; rather he said to him, “Get up,” implying that he should get up and go back to his wife. This is indicative of the Prophet’s good attitude and how gentle he was with people. This hadith indicates that a father may enter his daughter’s house without the permission of her husband, if he knows that her husband approves of that. It indicates that one may joke with one who is angry, and call him by a kunyah other than his own, if that will not upset him or make him angry; rather it will comfort him. It indicates that it is permissible to give someone a kunyah that is not based on his child’s name. It highlights the great virtue of ‘Ali ibn Abi Talib (may Allah be pleased with him). It indicates that it is permissible to sleep in the mosque at any time..