From Sahih Muslim (Hadith 2986):
Hafsa (Allah be pleased with her) reported:I said to Allah's Messenger (ﷺ): What is the matter with people that they have put off Ihram, whereas you have not put it off after your Umra'? He said: I have driven my sacrificial animal and stuck my hair, and it is not permissible for me to put off Ihram unless I have completed the Hajj
Reference: Muslim 2986