Musannaf Ibn Abi Shayba 22:256

Malik narrated to us, Abu Qudama narrated to us, he said: Abu Imran al-Jawni narrated to us, from Jundub ibn Abdullah, he said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Recite the Quran as long as your hearts are in agreement over it. But when you differ regarding it, then stand up [and leave]."