2 Samuel 2:30

“And Joab returned from following Abner, etc.] It being in his commission from David to shed as little blood as he could: and when he had gathered all the people together; who had been pursuing the Israelites, some one way and some another: there lacked of David’s servants nineteen men, and Asahel; who is particularly mentioned, because a very honourable man, valiant and courageous, a relation of David, and brother of Joab the general, and the loss of him was greater than all the rest. This has made some think that the twelve men of the servants of David were not killed in the duel, or otherwise there must be but seven slain in the battle; though that is not more strange than that in the…”

“Joab also assembled his men for a retreat. Nineteen of his soldiers were missing besides Asahel, all of whom had fallen in the battle. But they had slain as many as three hundred and sixty of Benjamin and of Abner's men. This striking disproportion in the numbers may be accounted for from the fact that in Joab's army there were none but brave and well-tried men, who had gathered round David a long time before; whereas in Abner's army there were only the remnants of the Israelites who had been beaten upon Gilboa, and who had been still further weakened and depressed by their attempts to recover the land which was occupied by the Philistines. 2 Kings (2 Samuel) 2:32”