181 Then David mustered the men who were with him, and set over them commanders of thousands and commanders of hundreds. 2 And David divided the army into three groups: one third under the command of Joab, one third under the command of Abishai son of Zeruiah, Joab's brother, and one third under the command of Ittai the Gittite. The king said to the men, "I myself will also go out with you." 3 But the men said, "You shall not go out. For if we flee, they will not care about us. If half of us die, they will not care about us. But you are worth ten thousand of us; therefore it is better that you send us help from the city." 4 The king said to them, "Whatever seems best to you I will do." So the king stood at the side of the gate, while all the army marched out by hundreds and by thousands.
Matthew Henry's Commentary on 2 Samuel 18:1-4
Commentary on 2 Samuel 18:1-8
(Read 2 Samuel 18:1-8)
How does David render good for evil! Absalom would have only David smitten; David would have only Absalom spared. This seems to be a 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 see what it is to take counsel against the Lord and his anointed.