"The Prophet wiped his head and his ears: the outside and the inside of them." ($ahih)
Jami` at-Tirmidhi Book 1, Hadith 36
← Previous Hadith he saw the Prophet performing Wudu, and that he wiped his head with water that was not left over from his hands.

Jami` at-Tirmidhi Book 1, Hadith 35 Next Hadith → "The Prophet performed Wudu; so he washed his face three times, and his hands three times, and wiped his head, and he said: "The ears are part of the head."

Jami` at-Tirmidhi Book 1, Hadith 37