Musnad Abu Ya'la al-Mawsili 130:37

Ja'far ibn Mihran narrated to us, 'Abd al-Warith narrated to us, from 'Abd al-'Aziz, from Anas, who said: The Messenger of Allah (may Allah bless him and grant him peace) did not come out to us for three [days]. Then the prayer was called, and Abu Bakr went to step forward. The Messenger of Allah (may Allah bless him and grant him peace) gestured toward the curtain, and he lifted it. When the whiteness of the face of the Messenger of Allah (may Allah bless him and grant him peace) became clear to us, we had never looked at a sight more pleasing to us than the face of the Prophet of Allah (may Allah bless him and grant him peace) when it became clear to us. He said: The Prophet (may Allah bless him and grant him peace) gestured to Abu Bakr to step forward. He said: And the Messenger of Allah (may Allah bless him and grant him peace) let the curtain down, and we did not see him again until he died.