Musannaf Ibn Abi Shaybah 9865 — How many days there are in a month

Sayyidah Aishah (may Allah be pleased with her) said: May Allah forgive Abu Abd al-Rahman. The Prophet (peace and blessings be upon him) only stayed away from his wives for a month, and he came down after twenty-nine days. The people said: "O Messenger of Allah! You took an oath for a month?" He said: "The month can be twenty-nine days."