'Executing' in the Bible

For the Levites left their suburbs and their possession, and came to Judah and Jerusalem: for Jeroboam and his sons had cast them off from executing the priest's office unto the LORD:

And it came to pass, that, when Jehu was executing judgment upon the house of Ahab, and found the princes of Judah, and the sons of the brethren of Ahaziah, that ministered to Ahaziah, he slew them.