Sahih Muslim Book 7, Hadith Number 2788.

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.

‘Aisha (Allah be pleased with her) reported that she entered in the monthly period at Sarif, and took bath at ‘Arafa (after the period was over). The messenger of Allah (may peace be upon him) said to her: Your circumambulation between al Safa and al-Marwa is enough for your Hajj and ‘Umra.