When the Day of Tarwiyah came, they set out for Mina and entered the state of ihram for Hajj... the rest of the hadith.
… فلما كان يوم التروية توجهوا إلى منى، فأهلوا بالحج… الحديث.
Muslim narrated it in Hajj (1218) via Hatim bin Ismail Madani, from Jafar bin Muhammad, from his father, from Jabir, and he related it at length concerning the Prophet's ﷺ hajj. In another version of his (1213), via Layth, from Abu Zubayr, from Jabir, with the wording, "Then we entered ihram on the day of Tarwiya."In another version of his (1214), via Yahya bin Saeed (that is, Qattan), from Ibn Jurayj, who said, Abu Zubayr informed me, with the same chain, with the wording, "The Prophet ﷺ commanded us, when we had come out of ihram, to enter ihram again once we set out for Mina." He said, "So we entered ihram from Abtah."In another version of his (1216:142), via Ataa, from Jabir, who said, "Until when it was the day of Tarwiya and we had left Makkah behind us, we entered ihram for the hajj."