On the day of al-Harrah, it was said to Abdullah bin Zayd, "Come to Ibn Hanzala, the people are pledging allegiance to him."He asked, "On what basis is he taking their pledge?"They replied, "On death."He said, "I will not pledge that to anyone after the Messenger of Allah ﷺ."
قال حدثنا مؤمل قال حدثنا وهيب قال حدثنا
قيل لعبد الله بن زيد يوم الحرة هلم إلى ابن حنظلة يبايع الناس قال علام يبايعهم قالوا على الموت قال لا أبايع عليه أحدا بعد رسول الله ﷺ
Its isnad is sahih. Bukhari narrated this hadith in 6/117, no. 2959, Fath, in the book of jihad, chapter on the pledge in war not to flee, and Muslim in 3/1486, no. 1861, in the book of leadership, chapter on the recommendation of the army pledging allegiance to the leader.The Ibn Hanzala meant in the hadith is Abdullah bin Hanzala bin Abu Amir, and Hanzala is the one known as the one washed by the angels, whose story is well known. His saying, "at the time of Harrah," means at the battle of Harrah, which took place in the time of Yazid bin Muawiya, in the year sixty-three.