Ester 9:24

9:24 For Haman the son of Hammedatha, the Agagite, the enemy of all the Jews, had devised plans against the Jews to destroy them. He had cast pur (that is, the lot) in order to afflict and destroy them.

Ester 9:26

9:26 For this reason these days are known as Purim, after the name of pur.