Musannaf Ibn Abi Shayba 9:926

Al-Fadl ibn Dukayn narrated to us, from Abu Hilal, from Shaybah ibn Hisham al-Rasibi, who said: I asked Salim about a man who lies with his wife while she is menstruating. He said: "As for us, the family of Umar, we isolate ourselves from them."