Musannaf Ibn Abi Shayba 1:1613

Waki’ narrated to us, from Hammad bin Salamah, from Khalid bin Abi al-Salt, from ‘Arak bin Malik, from ‘Aishah, who said: It was mentioned in the presence of the Messenger of Allah, may Allah bless him and grant him peace, that some people dislike facing the Qiblah with their private parts. The Messenger of Allah, may Allah bless him and grant him peace, said: "Face the Qiblah with your seats."