Musnad Ahmad 30:1120

And the Messenger of Allah, may Allah bless him and grant him peace, said: "While I was sleeping, I saw that I was drawing water from a cistern to give people to drink. Then Abu Bakr came to me and took the bucket from my hand to relieve me, and he drew two buckets, and there was weakness in his drawing." He said: "Then Ibn al-Khattab came to me—may Allah forgive him—and he took it from me. No man could draw [as he did] until the people had finished, and the cistern was gushing forth."