Musannaf Ibn Abi Shayba 19:687

Abu Bakr narrated to us, he said: Ibn Mahdi narrated to us, from Isra'il, from Salim, who said: I asked Sa'id ibn Jubayr about a man who marries a Jewish woman, a Christian woman, or a slave woman: Does he attain *ihsan* (chastity/legal status of a married person) through them? He said: Yes, even if it were for a day.