Musnad Ahmad 25:782

'Affan narrated to us, Wuhayb narrated to us, Ayyub narrated to us, from a man who said: I heard Ibn 'Abbas saying: The Messenger of Allah (ﷺ) and his companions arrived on the morning of the fourth [day of Dhu al-Hijjah], having entered into the state of Ihram for Hajj. The Messenger of Allah (ﷺ) commanded them to change it into an 'Umrah, except for those who had the sacrificial animals with them. He said: So we wore shirts, the incense burners were lit, and we had intercourse with women.