Sahih Muslim Book 7, Hadith Number 2798.

Chapter : Types of Ihram- It is permissible to enter into the state of Ihram singularly for the sake of Hajj or for tamattu’ bi’l-‘umra ila’l-Hajj or for both hajj and ‘umra together.

Jabir b. ‘Abdullah (Allah be pleased with them) reported: We entered with the Messenger of Allah (may peace be upon him) in the state of Ihram for Hajj. When we came to Mecca he commanded us to put on Ihram and make it for ‘Umra. We felt It (the command) hard for us, and our hearts were anguished on account of this and it (this reaction of the people) reached the Apostle of Allah (may peace be upon him). We do not know whether he received (this news) from the Heaven (through revelation) or from the people. (Whatever the case might be) he said; O people, put off Ihram. If there were not the sacrificial animals with me, I would have done as you do. So we put off the Ihram (after performing Umra), and we bad intercourse with our wives and did everything which a non-Muhrim does (applying perfume, putting on clothes, etc.), and when It was the day of Tarwiya (8th of Dhu’l-Hijja) we turned our back to Mecca (in order to go to Mini, ‘Arafat) and we put on ihram for Hajj.