Musnad Ahmad 33:609

Musa ibn Dawud narrated to us, Ibn Lahi'ah narrated to us, from Abu al-Zubayr, from Jabir: "That the Prophet, peace and blessings of Allah be upon him, called at the time of his death for a parchment so that he might write in it a document after which they would not go astray." He said: "Then Umar ibn al-Khattab disagreed regarding it until he rejected it."