We see in this instance how hard work, the sweat of toilsome labour, risk of life, weariness, wounds, and heroic endurance may all be accepted of God, may be poured out unto the Lord, though in the first instance shown to man. Every work done for others costing self-denial, weariness, and anxiety is like the water brought from the well of Bethlehem by the three valiant men of David. It does not rest with the immediate object; it is poured out in sacrifice to the Lord.
Unselfishness confers on him who is adorned with it a sort of priesthood. He is ever offering up sacrifices of his time, his comforts, his conveniences, to others, and though these be offered to others, they are in reality libations to God. There is special merit in such acts if they be done with a right intent, and in such a way that Christ may be seen in all we do for others.
S. Baring-Gould, Village Preaching for a Year, p.194.
References: 2 Samuel 23:15-17. J. Baines, Sermons,p. 126. 2 Samuel 23:20. S. Baring-Gould, One Hundred Sermon Sketches,p. 91. 2 Samuel 24 W. M. Taylor, David King of Israel,p. 269.