Sayyiduna Sahl bin Hunayf (may Allah be pleased with him) says: We set out with the Messenger of Allah (peace and blessings be upon him) intending Hajj, and we pronounced the talbiyah for Hajj. Then, when we reached Makkah, he (peace and blessings be upon him) ordered us to make it an Umrah.
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5592