Musnad Ahmad 32:2055

Muhammad ibn Ja'far narrated to us, Shu'bah narrated to us, from 'Abd al-'Aziz ibn Suhayb, who said: I heard Anas ibn Malik say: When the Messenger of Allah (peace and blessings of Allah be upon him) would come to the privy, he would say: "I seek refuge in Allah from the male devils and the female devils — or the foul things and the foul ones." Shu'bah said: "And he has said both of them."