Musannaf Ibn Abi Shayba 3:5604

Abu Bakr narrated to us, he said: Waki’ narrated to us, from Sufyan, from Suhayl ibn Abi Salih, from the son of Abu Sa’id al-Khudri, from his father, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "If one of you yawns during prayer, let him suppress it as much as he can, for the devil enters."