Musnad Ahmad 30:3586

Uthman ibn Umar narrated to us, Malik ibn Anas informed us, from al-Zuhri, Qabisah ibn Dhu'ayb informed me, that Abu Hurayrah informed him: That the Messenger of Allah (peace and blessings of Allah be upon him) forbade combining a woman and her paternal aunt, and a woman and her maternal aunt [in marriage].