Sunan Abu Dawud
4590
Sahih+3

Narrated Imran ibn Husayn: A servant of some poor people cut off the ear of the servant of some rich people. His people came to the Prophet (ﷺ) and said: Messenger of Allah! we are poor people. So he imposed no compensation on them

SahihAl-Albani
SahihMuhammad Muhyi Al-Din Abdul Hamid