Verses with the word avenge in the Old Testament (11 verses):

Leviticus 19:18
Thou shalt not avenge, nor bear any grudge against the children of thy people, but thou shalt love thy neighbour as thyself: I am the LORD.

Leviticus 26:25
And I will bring a sword upon you, that shall avenge the quarrel of my covenant: and when ye are gathered together within your cities, I will send the pestilence among you; and ye shall be delivered into the hand of the enemy.

Numbers 31:2
Avenge the children of Israel of the Midianites: afterward shalt thou be gathered unto thy people.

Numbers 31:3
And Moses spake unto the people, saying, Arm some of yourselves unto the war, and let them go against the Midianites, and avenge the LORD of Midian.

Deuteronomy 32:43
Rejoice, O ye nations, with his people: for he will avenge the blood of his servants, and will render vengeance to his adversaries, and will be merciful unto his land, and to his people.

1 Samuel 24:12
The LORD judge between me and thee, and the LORD avenge me of thee: but mine hand shall not be upon thee.

2 Kings 9:7
And thou shalt smite the house of Ahab thy master, that I may avenge the blood of my servants the prophets, and the blood of all the servants of the LORD, at the hand of Jezebel.

Esther 8:13
The copy of the writing for a commandment to be given in every province was published unto all people, and that the Jews should be ready against that day to avenge themselves on their enemies.

Isaiah 1:24
Therefore saith the LORD, the LORD of hosts, the mighty One of Israel, Ah, I will ease me of mine adversaries, and avenge me of mine enemies:

Jeremiah 46:10
For this is the day of the Lord GOD of hosts, a day of vengeance, that he may avenge him of his adversaries: and the sword shall devour, and it shall be satiate and made drunk with their blood: for the Lord GOD of hosts hath a sacrifice in the north country by the river Euphrates.

Hosea 1:4
And the LORD said unto him, Call his name Jezreel; for yet a little while, and I will avenge the blood of Jezreel upon the house of Jehu, and will cause to cease the kingdom of the house of Israel.