Abdullah bin Umar reported,

He divorced his wife while she was menstruating during the time of the Messenger of Allah ﷺ. Umar bin Khattab asked the Messenger of Allah ﷺ about this, and the Messenger of Allah ﷺ said to him, "Order him to take her back, then let him keep her until she becomes pure, then menstruates again, then becomes pure once more. After that, if he wishes, he may keep her, and if he wishes, he may divorce her before touching her. That is the waiting period that Allah commanded for divorcing women."

حدثنا يحيى بن يحيى التميمي قال قرأت على مالك بن أنس عن نافع

عن ابن عمر

أنه طلق امرأته وهي حائض في عهد رسول الله ﷺ فسأل عمر بن الخطاب رسول الله ﷺ عن ذلك فقال له رسول الله ﷺ مره فليراجعها ثم ليتركها حتى تطهر ثم تحيض ثم تطهر ثم إن شاء أمسك بعد وإن شاء طلق قبل أن يمس فتلك العدة التي أمر الله عز وجل أن يطلق لها النساء