20 Benaiah son of Jehoiada was a valiant warrior from Kabzeel, a doer of great deeds; he struck down two sons of Ariel of Moab. He also went down and killed a lion in a pit on a day when snow had fallen. 21 And he killed an Egyptian, a handsome man. The Egyptian had a spear in his hand; but Benaiah went against him with a staff, snatched the spear out of the Egyptian's hand, and killed him with his own spear 22 Such were the things Benaiah son of Jehoiada did, and won a name beside the three warriors. 23 He was renowned among the Thirty, but he did not attain to the Three. And David put him in charge of his bodyguard.
Matthew Henry's Commentary on 2 Samuel 23:20-23
Commentary on 2 Samuel 23:8-39
(Read 2 Samuel 23:8-39)
David once earnestly longed for the water at the well of Bethlehem. It seems to be an instance of weakness. He was thirsty; with the water of that well he had often refreshed himself when a youth, and it was without due thought that he desired it. Were his valiant men so forward to expose themselves, upon the least hint of their prince's mind, and so eager to please him, and shall not we long to approve ourselves to our Lord Jesus, by ready compliance with his will, as shown us by his word, Spirit, and providence? But David poured out the water as a drink-offering to the Lord. Thus he would cross his own foolish fancy, and punish himself for indulging it, and show that he had sober thoughts to correct his rash ones, and knew how to deny himself. Did David look upon that water as very precious which was got at the hazard of these men's blood, and shall not we much more value those benefits for purchasing which our blessed Saviour shed his blood? Let all beware of neglecting so great salvation.