2 Samuel 21:14-18
English Standard Version
15There was war again between the Philistines and Israel, and David went down together with his servants, and they fought against the Philistines. And David grew weary.
16And Ishbi-benob, one of the descendants of the giants, whose spear weighed three hundred shekels of bronze, and who was armed with a new sword, thought to kill David.
17But Abishai the son of Zeruiah came to his aid and attacked the Philistine and killed him. Then David 's men swore to him, "You shall no longer go out with us to battle, lest you quench the lamp of Israel."