Sahih Muslim Book 7, Hadith Number 2852.

Chapter : One who undertakes to perform Umra is not allowed to put off Ihram before Sai’ and the pilgrim and the (Qiran) is not allowed to put off ihram at Tawaf Qud’um (circumambulation of arrival).

Asma bint Abu Bakr (Allah be pleased with them) said: We came for Hajj in the state of Ihram with Allah’s Messenger (may peace be upon him). The rest of the Hadith is the same except (for the words) that he (Zubair) said: Keep away from me, keep away from me, whereupon I said: Do you fear that I will jump upon you?