Musannaf Ibn Abi Shayba 3:5530

Ubayd Allah ibn Musa narrated to us, from Musa ibn Ali, from Amr ibn Abi Amr, from Anas ibn Malik, who said: A man entered searching for a lost item in the mosque, and the Messenger of Allah (peace and blessings of Allah be upon him) heard his voice. He said: "May you not find it."