Musnad Ahmad 32:1621

'Affan narrated to us, Hammam narrated to us, from Qatadah, who said: I asked Anas: "How many times did the Messenger of Allah, peace and blessings of Allah be upon him, perform 'Umrah?" He said: "Four times: his 'Umrah from which the polytheists turned him away in Dhu al-Qa'dah, and his 'Umrah also in the following year in Dhu al-Qa'dah, and his 'Umrah when he distributed the spoils of Hunayn from al-Ji'ranah in Dhu al-Qa'dah, and his 'Umrah with his Hajj."