Musnad Abu Ya'la al-Mawsili 3:100

Abu Khaythama narrated to us, al-Hasan ibn Musa narrated to us, Abdullah ibn Lahi'ah narrated to us, Abdullah ibn Hubayrah narrated to us, from Abdullah ibn Zurayr, from Ali ibn Abi Talib, that the Prophet (peace and blessings of Allah be upon him) forbade that a woman be married [at the same time] as her paternal aunt or her maternal aunt.