Musnad Ahmad 1098:2

Husayn—meaning Ibn Muhammad—narrated to us, Al-Fudayl—meaning Ibn Sulayman—narrated to us, Muhammad ibn Abi Yahya narrated to us, from Ubayd Allah ibn Khunays al-Ghifari, from Abdullah ibn Salam, who said: "Between such-and-such and Uhud is a sanctuary, which the Messenger of Allah (peace and blessings of Allah be upon him) made sacred. I would not cut a tree in it, nor would I kill a bird in it."