Three times
2 Kings 13:18
And he said, Take the arrows. And he took them. And he said unto the king of Israel, Smite upon the ground. And he smote thrice, and stayed.
2 Kings 13:19
And the man of God was wroth with him, and said, Thou shouldest have smitten five or six times; then hadst thou smitten Syria till thou hadst consumed it: whereas now thou shalt smite Syria but thrice.