Sayyiduna Ibn Abbas (may Allah be pleased with them both) narrates that during the Farewell Hajj, when the Prophet (peace and blessings be upon him) ordered the people to perform Umrah and leave the state of ihram, a man would come and say: "O Messenger of Allah! But this is Hajj." the Messenger of Allah (peace and blessings be upon him) would say: "It is not Hajj; rather, it is Umrah."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 12135