From Sahih Muslim (Hadith 3007):
Muslim al-Qurri heardlbn 'Abbas (Allah be pleased with them) saying that Allah's Apostle (ﷺ) entered into the state of Ihram for Umra and his Companions for Hajj. Neither Allah's Apostle (ﷺ) nor those among his Companions who had brought sacrificial animals with them put off Ihram, whereas the rest (of the pilgrims) did so. Talha b. Ubaidullah was one of those who had brought the sacrificial animals along with them so he did not put off Ihram
Reference: Muslim 3007