Musannaf Ibn Abi Shayba 9:1532

Marwan ibn Mu'awiyah narrated to us, from Ibn 'Awn, from Muhammad ibn Sirin, who said: Umar ibn al-Khattab said: "Nothing remains of the morals of the Jahiliyyah except that I do not care which of the Muslims I marry, and which of them I give in marriage."