Musnad Ahmad 30:345

Abu Amir narrated to us, Hisham narrated to us, from Yahya, from Abu Salamah, from Abu Hurairah, that the Prophet, peace and blessings of Allah be upon him, said: "A woman shall not be married—or he said: A woman shall not be wed—while her paternal aunt is [also married to the same man], nor while her maternal aunt is [also married to the same man]."