Sahih Muslim | Book 7 | Hadith Number 2769

Narrated by 'Aisha (Allah be pleased with her)
'Aisha (Allah be pleased with her) said: We set out with the Messenger of Allah (may peace be upon him) just at the appearance of the new moon of Dhu'l-Hijja. We had no other intention but that of performing the Hajj, whereupon the Messenger of Allah (may peace be upon him) said: He who among you intends to put on Ihram for 'Umra should do so for 'Umra. The rest of the hadith is the same.