Musnad Ahmad 1179:2

Abu Mu'awiyah narrated to us, Al-A'mash narrated to us, from Abu Sufyan, from Jabir, from Umm Mubashir, she said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever plants a plant, or sows a crop, and a human, or a beast of prey, or a beast, or a bird eats from it, then it is a charity for him."