Sahih Bukhari Volume 4, Book 52, Hadith Number 206.

Narated By ‘Abdullah bin Zaid : That in the time (of the battle) of Al-Harra a person came to him and said, “Ibn Hanzala is taking the pledge of allegiance from the people for death.” He said, “I will never give a pledge of allegiance for such a thing to anyone after Allah’s Apostle.”