Sunan Ibn Majah Book 10, Hadith 9

"I said to Fatimah bint Qais: 'Tell me about your divorce.' She said: 'My husband divorced me three times when he was leaving for Yemen, and the Messenger of Allah (ﷺ) allowed that."'

← Previous Hadith he divorced his wife when she was menstruating, and 'Umar mentioned that to the Prophet (ﷺ). He said: "Tell him to take her back then divorce her when she is pure (not menstruating) or pregnant."

Sunan Ibn Majah Book 10, Hadith 8 Next Hadith → was asked about a man who divorced his wife then had intercourse with her, and there were no witnesses to his divorcing her or his taking her back. 'Imran said: "You have divorced (her) in a manner that is not according to the Sunnah, and you have taken her back in a manner that is not according to the Sunnah. Bring people to witness your divorcing her and taking her back."

Sunan Ibn Majah Book 10, Hadith 10