It is narrated from Hazrat Anas (may Allah be pleased with him) that once the Prophet (peace and blessings be upon him) sprained his foot and he stayed in his upper chamber, which had wooden stairs, and he took an oath of abstention (ila) from his pure wives for a month. The noble companions (may Allah be pleased with them) came to visit the Prophet (peace and blessings be upon him), so the Prophet (peace and blessings be upon him) led them in prayer while sitting, whereas the companions (may Allah be pleased with them) remained standing. When the time for the next prayer came, the Prophet (peace and blessings be upon him) said to them: Follow your Imam; if he prays standing, then you should also pray standing, and if he prays sitting, then you should also pray sitting with him. In short, after 29 days had passed, the Prophet (peace and blessings be upon him) came down. The people asked, "O Messenger of Allah (peace and blessings be upon him)! You had taken an oath of abstention for a month?" The Prophet (peace and blessings be upon him) replied, "Sometimes a month is also of 29 days."