Musnad Ahmad 814:1

Muhammad ibn Ja‘far narrated to us, Shu‘bah narrated to us, he said: I heard ‘Ali ibn Zayd narrating from Zurarah ibn Awfa, from a man of his people who is called Malik, or Ibn Malik, narrating from the Prophet, may Allah bless him and grant him peace, that he said: "Any Muslim who takes an orphan between two Muslim parents into his food and drink until he becomes independent, Paradise becomes mandatory for him, absolutely. And any Muslim who frees a slave, or a Muslim man, it is his ransom from the Fire. And whoever reaches his parents, or one of them, then enters the Fire, may Allah distance him."