Musannaf Ibn Abi Shayba 22:80

Zayd ibn al-Hubab narrated to us, from Musa ibn Ali, who said: I heard my father say: I heard Uqbah ibn Amir say: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Learn the Quran and spread it. By the One in Whose hand is my soul, it is more prone to escape than the camel is from its hobble."