It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that he heard a question being asked about a man who divorces his wife during her menstrual period. He said: "Do you know Abdullah bin Umar (may Allah be pleased with him)?" The questioner said: "Yes." He said: "He also divorced his wife during her menstrual period. Sayyiduna Umar (may Allah be pleased with him) went and informed the Noble Prophet (peace and blessings be upon him) about this, so the Noble Prophet (peace and blessings be upon him) said: 'Tell him to take her back.'"