Musnad Abu Ya'la al-Mawsili 109:269

Kamil narrated to us, Layth narrated to us, he said: Abu al-Zubayr, the freed slave of Hakim ibn Hizam, narrated to me, from Jabir, that when they were present with the Messenger of Allah (may Allah bless him and grant him peace), he would send the sacrificial animals (al-hady). So whoever among us wished would enter into Ihram, and whoever among us wished would refrain.