Musnad Ahmad 30:2483

Yahya ibn Sa'id narrated to us, from Yazid ibn Kaysan, who said: Abu Hazim narrated to me, saying: I saw Abu Hurayrah gesturing with his two fingers repeatedly: "By the One in whose hand is the soul of Abu Hurayrah, the Prophet of Allah, peace and blessings of Allah be upon him, and his family did not eat their fill of wheat bread for three consecutive days, until he departed from the world."