Ibn Sirin محمد بن سيرين الأنصاري · Divorce (Kitab Al-Talaq)

‘Abd Allah (bin Umar) said that he divorced his wife while she was menstruating. ‘Umar mentioned the matter to the Messenger of Allah(ﷺ). The Messenger of Allah(ﷺ) became angry and said “Command him, he must take her back and keep her back till she is purified, then has another menstrual period and is purified. Then if he desires he may divorce her during the period of purity before he has intercourse with her. This is the divorce for waiting period…

Yunus bin Jubair said that he asked Ibn ‘Umar “How many times did you pronounce divorce to your wife? He replied, once.”