Sahih Bukhari Volume 003, Book 027, Hadith Number 006.
Narated By Qatada : I asked Anas how many times the Prophet had performed 'Umra. He replied, "Four times. 1. 'Umra of Hudaibiya in Dhi-l-Qa'da when the pagans hindered him; 2. 'Umra in the following year in Dhi-l-Qa'da after the peace treaty with them (the pagans); 3. 'Umra from Al-Jr'rana where he distributed the war booty." I think he meant the booty (of the battle) of Hunain. I asked, "How many times did he perform Hajj?" He (Anas) replied, "Once. "