فَإِذَا كَانَ يَوْمُ التَّرْوِيَةِ أَحْرَمَ بِالْحَجِّ مِنَ الْمَسْجِدِ، وَفَعَلَ مَا يَفْعَلُهُ الْحَاجُّ الْمُفْرِدُ
Translation: On the Day of Tarwiyah he enters ihram for Hajj from the mosque and performs the rites followed by the pilgrim doing ifrad.
Yawm al-Tarwiyah is 8 Dhu al-Hijjah. The mosque is named in the described procedure, not as the only place from which every pilgrim’s Hajj ihram could be valid. Subsequent rites include Mina, Arafat and Muzdalifah.