And some have said that (the pledge was) upon death, because Allah the Exalted has said in Surah Al-Fath «لقد رضي الله عن المؤمنين إذ يبايعونك تحت الشجرة‏» "Indeed, Allah was pleased with the believers when they gave you the pledge under the tree (the Pledge of Ridwan)."

Narrated Ibn `Umar: When we reached (Hudaibiya) in the next year (of the treaty of Hudaibiya), not even two men amongst us agreed unanimously as to which was the tree under which we had given the pledge of allegiance, and that was out of Allah's Mercy. (The sub narrator asked Naf'i, "For what did the Prophet take their pledge of allegiance, was it for death?" Naf'i replied "No, but he took their pledge of allegiance for patience.")