Charles Ellicott Commentary 2 Samuel 24:24

"And the king said unto Araunah, Nay; but I will verily buy it of thee at a price. Neither will I offer burnt-offerings unto Jehovah my God which cost me nothing. So David bought the threshing-floor and the oxen for fifty shekels of silver." — 2 Samuel 24:24 (ASV)

Of that which cost me nothing.—The principle on which David acted is that which essentially underlies all true sacrifice and all real giving to God.

For fifty shekels of silver.—This sum is expressly said to cover the cost both of the ground and of the oxen, and seems very small. In 1 Chronicles 21:25, it reads six hundred shekels of gold by weight. One of the most ingenious propositions for the reconciliation of the two statements is that our text speaks of fifty shekels, not of silver but of money, and that Chronicles means that these were of gold, in value equal to 600 shekels of silver.

But the explanation is quite inconsistent with the text in both places. In one of them the statement of price must have been altered in transcription. In the entire uncertainty as to the extent of the purchase of Araunah (the whole hill of Moriah, or only a part), and of the value of land in the locality and at the time, it is impossible to decide between the two.