Sahih Muslim
The Book of Transactions (Kitab Al-Buyu)
Book Number: 010 / Hadith Number: 3766
Jabir b. 'Abdullah (Allah be pleased with them) reported: I heard Allah's Messenger (may peace be upon him) saying: Never does a Muslim plant, or cultivate, but has reward for him for what the beasts eat, or the birds eat or anything else eats out of that.