John Gill's Bible Commentary Ver. 7. Where the people of Israel were slain before the servants of David , etc.] That is, the people of Israel that were under Absalom, these were beaten by David’s army: and there was a great slaughter that day of twenty thousand [men] ; including both those that fell in the field of battle, and that were slain in the pursuit; and this is to be understood only of Absalom’s party.
Matthew Henry Commentary
Verses 1-8 - How does David render good for evil! Absalom would have only Davi smitten; David would have only Absalom spared. This seems to be resemblance of man's wickedness towards God, and God's mercy to man, of which it is hard to say which is most amazing. Now the Israelites se what it is to take counsel against the Lord and his anointed.
Original Hebrew וינגפו5062 שׁם8033 עם5971 ישׂראל3478 לפני6440 עבדי5650 דוד1732 ותהי1961 שׁם8033 המגפה4046 גדולה1419 ביום3117 ההוא1931 עשׂרים6242 אלף׃505