20 Benaiah son of Jehoiada from Kabzeel was a vigorous man who accomplished a great deal. He once killed two lion cubs in Moab. Another time, on a snowy day, he climbed down into a pit and killed a lion. 21 Another time he killed a formidable Egyptian. The Egyptian was armed with a spear and Benaiah went against him with nothing but a walking stick; he seized the spear from his grip and killed him with his own spear 22 These are the things that Benaiah son of Jehoiada is famous for. But neither did he ever get ranked with the Three. 23 He was held in greatest respect among the Thirty, but he never got included with the Three. 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.