Sahih Bukhari

Narrated Sa`id bin `Amr bin Sa`id bin Al-`Aas:Al-Hajjaj went to Ibn `Umar while I was present there. Al-Hajjaj asked Ibn `Umar, ""How are you?"" Ibn `Umar replied, ""I am all right,"" Al-Hajjaj asked, ""Who wounded you?"" Ibn `Umar replied, ""The person who allowed arms to be carried on the day on which it was forbidden to carry them (he meant Al-Hajjaj)