2 Samuel 12:3

12:3 But the poor man had nothing except for a little lamb he had acquired. He raised it, and it grew up alongside him and his children. It used to eat his food, drink from his cup, and sleep in his arms. It was just like a daughter to him.

2 Samuel 24:24

24:24 But the king said to Araunah, “No, I insist on buying it from you! I will not offer to the Lord my God burnt sacrifices that cost me nothing.”

So David bought the threshing floor and the oxen for fifty pieces of silver.