18 And Gad came that day to David and said to him, "Go up, erect an altar to the Lord on the threshing floor of Araunah the Jebusite." 19 So David, according to the word of Gad, went up as the Lord commanded. 20 Now Araunah looked, and saw the king and his servants coming toward him. So Araunah went out and bowed before the king with his face to the ground. 21 Then Araunah said, "Why has my lord the king come to his servant?" And David said, "To buy the threshing floor from you, to build an altar to the Lord, that the plague may be withdrawn from the people." 22 Now Araunah said to David, "Let my lord the king take and offer up whatever seems good to him. Look, here are oxen for burnt sacrifice, and threshing implements and the yokes of the oxen for wood. 23 All these, O king, Araunah has given to the king." And Araunah said to the king, "May the Lord your God accept you." 24 Then the king said to Araunah, "No, but I will surely buy it from you for a price; nor will I offer burnt offerings to the Lord my God with that which costs me nothing." So David bought the threshing floor and the oxen for fifty shekels of silver.
Matthew Henry's Commentary on 2 Samuel 24:18-24
Commentary on 2 Samuel 24:18-25
(Read 2 Samuel 24:18-25)
God's encouraging us to offer to him spiritual sacrifices, is an evidence of his reconciling us to himself. David purchased the ground to build the altar. God hates robbery for burnt-offering. Those know not what religion is, who chiefly care to make it cheap and easy to themselves, and who are best pleased with that which costs them least pains or money. For what have we our substance, but to honour God with it; and how can it be better bestowed? See the building of the altar, and the offering proper sacrifices upon it. Burnt-offerings to the glory of God's justice; peace-offerings to the glory of his mercy. Christ is our Altar, our Sacrifice; in him alone we may expect to escape his wrath, and to find favour with God. Death is destroying all around, in so many forms, and so suddenly, that it is madness not to expect and prepare for the close of life.