Sunan Abu Dawud
1806
Sahih+3

Hafsah, wife of the Prophet (ﷺ) said Apostle of Allaah(ﷺ), how is it that the people have put off their ihram and you did not put off your ihram after your ‘Umrah. He said I have matted my hair and garlanded my sacrificial animal, so I shall not put off my ihram till I sacrifice my sacrificial animals

SahihAl-Albani
SahihMuhammad Muhyi Al-Din Abdul Hamid