Be of good courage, and let us play the men
This Joab said, not only to encourage Abishai and himself, but in the hearing of the rest of the officers of the army, and of many of the people, to hearten them to the battle; who might be somewhat intimidated with the number of their enemies, and the position they were in, being before and behind them; and therefore he thought proper to make such a speech to them to animate them to light:
for our people, and for the cities of our God;
that the people of Israel might not be carried captive, and their cities spoiled and plundered; and instead of being cities where the people of God dwelt, and he was worshipped, would, if taken, become the habitations of idolatrous Heathens, and where temples would be erected to idols, and the worship of them; these were the arguments he used to engage them to fight manfully for their country, the liberties and religion of it:
and the Lord do that which seemeth him good:
tacitly suggesting that victory was of the Lord, and that it became them to do their part in fighting courageously, and leave the issue to the Lord, on whom alone success depended.