The Second Book of Samuel (Commonly Called The Second Book of Kings )

And David numbered the people who were with him, and set captains of thousands and captains of hundreds over them.

Then David sent out one third of the people under the hand of Joab, one third under the hand of Abishai the son of Zeruiah, Joab's brother, and one third under the hand of Ittai the Gittite. And the king said to the people, "I also will surely go out with you myself."

But the people answered, "You shall not go out. For if we flee away, they will not care about us; nor if half of us die, will they care about us. But you are worth ten thousand of us now. For you are now more help to us in the city."

So the king said to them, "Whatever seems best to you I will do." So the king stood beside the gate, and all the people went out by hundreds and by thousands.

Now the king had commanded Joab, Abishai, and Ittai, saying, "Deal gently for my sake with the young man Absalom." And all the people heard when the king gave all the captains orders concerning Absalom.