Sayyiduna Ma'qil bin Yasar (may Allah be pleased with him) said: "I saw myself on the Day of the Tree, when the Prophet (peace and blessings be upon him) was taking the pledge of allegiance from the people, and I was holding one of its branches away from his (peace and blessings be upon him) head. We did not pledge to him unto death; rather, we pledged to him that we would not flee."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17666