Musnad Ahmad 28:294

Muhammad ibn Ja'far narrated to us, Husayn al-Mu'allim narrated to us, from 'Amr ibn Shu'ayb, from his father, from his grandfather, that the Messenger of Allah (may Allah bless him and grant him peace), when he conquered Makkah, said: "A woman shall not be married [at the same time] as her paternal aunt, nor [at the same time] as her maternal aunt."