Musnad Ahmad 32:1247

Sulayman and Abu Sa’id—meaning the freed slave of Banu Hashim—narrated to us, they said: Shu’bah narrated to us, he said: Musa ibn Anas narrated to us, he heard Anas, from the Prophet, may Allah bless him and grant him peace, that he said: "If you knew what I know, you would laugh little and weep much."