"The Prophet swore an oath of abstention from his wives for a month and stayed in his room for twenty-nine days. It was said: 'O Messenger of Allah, did you not swear an oath of abstention for a month?' He said: 'This month is twenty-nine days.'"
Sunan an-Nasa'i Book 27, Hadith 68
← Previous Hadith "One morning, we saw the wives of the Prophet weeping, and each one of them had her family with her. I entered the Masjid and found it filled with people. Then 'Umar, may Allah be pleased with him, came, and went to the Prophet who was in his room. He greeted him with the Salam but no one answered. He greeted him again but no one answered. He greeted him (a third time) but no one answered. So he went back and called out: 'Bilal!' He came to the Prophet and said: 'Have you divorced your wives?' He said: 'No, but I have sworn an oath of abstention from them for a month.' So he stayed away from them for twenty-nine days, then he came and went into his wives."

Sunan an-Nasa'i Book 27, Hadith 67 Next Hadith → "O Messenger of Allah, I declared Zihar on my wife, then I had intercourse with her before I offered the expiation." He said: "What made you do that, may Allah have mercy on you?" He said: "I saw her anklets in the light of the moon." He said: "Do not approach her until you have done that which Allah, the Mighty and Sublime, has commanded."

Sunan an-Nasa'i Book 27, Hadith 69