The Second Instance of Devotedness

It has often been pointed out that Joab is not listed among David's mighty men in 2 Sam. 23, though both his brothers and his armor bearer are listed there. It is in this chapter that we see the second example of the outstanding devotedness of Abishai. I believe that Abishai was one of the three men spoken of in 2 Sam. 23:16.
And the three mighty men brake through the host of the Philistines, and drew water out of the well of Bethlehem, that was by the gate, and took it, and brought it to David: nevertheless he would not drink thereof, but poured it out unto the Lord.... And Abishai, the brother of Joab, the son of Zeruiah, was chief among three. And he lifted up his spear against three hundred, and slew them, and had the name among three. (vv. 16,18.)
Here we find one of the most extraordinary examples of devotion in Scripture. How it delights our hearts to think of these three men. Though having received no order from David, yet his wish becomes a command to them. And at what personal cost it was! It seems from David's comments that he recognized that he was truly unworthy of such devotion. But it appears that so great was the affection of Abishai, that no personal sacrifice was too great, if by it some good and blessing might come to David.