Because

1 Kings 20:34
Ben-hadad said to him, "I will restore the cities my father took from your father; you may set up your own marketplaces in Damascus, as my father did in Samaria." "By this covenant I release you, " Ahab replied. So he made a treaty with him and sent him away.

1 Kings 22:31-37
Now the king of Aram had ordered his thirty-two chariot commanders, "Do not fight with anyone, small or great, except the king of Israel." . . .

1 Samuel 15:9-11
Saul and his troops spared Agag, along with the best of the sheep and cattle, the fat calves and lambs, and the best of everything else. They were unwilling to destroy them, but they utterly destroyed all that was despised and worthless. . . .

thy life shall go

1 Kings 22:31-37
Now the king of Aram had ordered his thirty-two chariot commanders, "Do not fight with anyone, small or great, except the king of Israel." . . .

2 Kings 6:24
Some time later, Ben-hadad king of Aram assembled his entire army and marched up to besiege Samaria.

2 Kings 8:12
"Why is my lord weeping?" asked Hazael. "Because I know the evil you will do to the Israelites, " Elisha replied. "You will set fire to their fortresses, kill their young men with the sword, dash their little ones to pieces, and rip open their pregnant women."

2 Chronicles 18:33, 34
However, a certain man drew his bow without taking special aim, and he struck the king of Israel between the joints of his armor. So the king said to his charioteer, "Turn around and take me out of the battle, for I am badly wounded!" . . .