Musannaf Ibn Abi Shayba 36:32

Waki' narrated to us, from Hammad ibn Salamah, from Thabit, from Anas, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "I have been harmed for the sake of Allah, and no one is harmed [like that]. And I have been made to fear for the sake of Allah, and no one is made to fear [like that]. And there came upon me three days and nights, and neither I nor Bilal had any food that a living creature could eat, except for what Bilal could hide under his armpit."