Musnad Abu Ya'la al-Mawsili 108:141

And from Jabir, he said: We did not pledge allegiance to the Messenger of Allah, may Allah bless him and grant him peace, at the time of al-Hudaybiyyah upon death, but we pledged allegiance to him that we would not flee, except for Jadd ibn Qays, who hid under the armpit of his camel.