Sahih Muslim Book 7, Hadith Number 3156.

Chapter : Eminence of Medina, Allah’s Apostle (may peace be upon him) showered blessings upon it. Its sacredness and unlawfulness of hunting and lopping of trees and demarcation its precincts.

‘Amir b. Sa’d reported that Sa’d rode to his castle in al-‘Aqiq and found a slave cutting down the trees, or beating off their leaves, so he stripped him off his belongings. When Sa’d returned, there came to him the masters of the slave and negotiated with him asking him to return to their slave or to them what he had taken from their slave, whereupon he said: God forbid that I should return anything which Allah’s Messenger (may peace be upon him) has given me as spoil, and refused to return anything to them.