Musannaf Ibn Abi Shayba 9:866

Yazid ibn Harun narrated to us, from Husayn al-Mu'allim, from Amr ibn Shu'ayb, from his father, from his grandfather, that the Prophet (may Allah bless him and grant him peace) said on the day of the conquest of Mecca: "A woman shall not be married [at the same time] as her paternal aunt, nor [at the same time] as her maternal aunt."