Musnad Ahmad 32:432

Bahz and Abd al-Samad narrated to us—the meaning is the same—they said: Hammam ibn Yahya narrated to us, Qatadah narrated to us, he said: I asked Anas ibn Malik, I said: "How many times did the Messenger of Allah, peace and blessings of Allah be upon him, perform Hajj?" He said: "One Hajj, and he performed Umrah four times: his Umrah at the time of al-Hudaybiyyah, his Umrah in Dhu al-Qa'dah from Medina, his Umrah from al-Ji'ranah in Dhu al-Qa'dah when he distributed the spoils of Hunayn, and his Umrah with his Hajj."