Musnad Ahmad 30:2107

'Attab narrated to us, 'Abdullah narrated to us, he said: Layth ibn Sa'd informed us, from al-Hasan ibn Thawban, I believe from Musa ibn Wardan, he said: Abu Hurayrah said to a man: "Come, let me bid you farewell as the Messenger of Allah (may Allah bless him and grant him peace) bade me farewell," or "as the Messenger of Allah (may Allah bless him and grant him peace) bade farewell: 'I entrust you to Allah, whose trusts are never lost.'"