Sunan Abi Dawud

Narrated 'Abd Allah b. 'Umar: That the Messenger of Allah (ﷺ) said: O Allah, have mercy on those who have themselves shaved. The people said: Messenger of Allah, and those who have clipped their hair. He again said: O Allah, have mercy on those who have themselves shaved. The people said: Messenger of Allah, those who have clipped their hair. He said: and those who clip their hair.