Sahih Bukhari
Fighting for the Cause of Allah (Jihaad)
Volume: 004 / Book Number: 052 / Hadith Number: 206
Narrated '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."