Musnad Ahmad 117:0

It was narrated from Takhfah ibn Qays al-Ghifari, who said: I was lying on my stomach in the mosque during the latter part of the night. A man began to move me with his foot and said, "This is a posture that Allah hates." I looked up, and it was the Messenger of Allah (peace and blessings of Allah be upon him). He said: I went out to the mosque one night, and I was lying on my stomach. A man moved me with his foot and said, "O you, this is a posture that Allah hates." I looked, and it was the Messenger of Allah (peace and blessings of Allah be upon him).