Musnad Ahmad 1223:0

Narrated to us by Yahya ibn Sa’id, from Muhammad ibn ‘Amr, from Abu Salamah, from Jaddah Rabah ibn ‘Abd al-Rahman: She said: I entered upon the Prophet (ﷺ) while he was in the house of Maymunah, and he was performing ablution. I saw him washing his head, and he poured water over his head three times. She said: And I saw him eating with three fingers.