Musnad Ahmad 962:153

Abu al-Mughirah narrated to us, Ma'an ibn Rifa'ah narrated to us, Ali ibn Yazid narrated to me, al-Qasim, the freed slave of Banu Yazid, narrated to me, from Abu Umamah al-Bahili, who said: When it was the Farewell Pilgrimage, the Messenger of Allah (peace and blessings of Allah be upon him) stood up—and he was on that day having al-Fadl ibn Abbas riding behind him on a tawny camel—and he said: "O people, take knowledge before knowledge is seized and before knowledge is lifted. Allah, the Mighty and Majestic, had revealed: 'O you who have believed, do not ask about things which, if they are shown to you, will distress you. But if you ask about them while the Qur'an is being revealed, they will be shown to you. Allah has pardoned that; and Allah is Forgiving and Forbearing' [al-Ma'idah: 101]." He said: We had disliked much of his questioning, and we avoided that until Allah revealed [that] to His Prophet (peace and blessings of Allah be upon him). He said: So we came to a Bedouin and bribed him with a cloak. He said: So he wrapped it around his head until I saw the edge of the cloak coming out from his right eyebrow. He said: Then we said to him: "Ask the Prophet (peace and blessings of Allah be upon him)." He said: So he said to him: "O Prophet of Allah, how will knowledge be lifted from us while the copies of the Qur'an are among us, and we have learned what is in them, and we have taught our women, our offspring, and our servants?" He said: So the Prophet (peace and blessings of Allah be upon him) raised his head, and a redness of anger had covered his face. He said: So he said: "Woe to you, may your mother be bereaved of you! These Jews and Christians have the copies of the Qur'an among them, yet they do not wake up holding onto a single letter of what their prophets brought them. Verily, part of the departure of knowledge is that its bearers depart." [He said this] three times.