2 Samuel 24:24
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.
An oxymoron is two words put together that seem to contradict each other. Our language is sprinkled with such paradoxical phrases, although we often are not consciously aware of them. For example, we talk about eating "jumbo shrimp," driving by a "sanitary landfill" or seeing something we describe as "pretty ugly." But there is another oxymoron that often exists in our thoughts if not in our language--it's called a "free sacrifice."
When David sinned by taking a census of the people, a plague ravished the land for three days. As the angel of the Lord stretched out his hand to strike Jerusalem, however, God stopped him and spared the city (2 Sam. 24:16). This took place at the threshing floor of Araunah the Jebusite. In response to this act of mercy, David was instructed to erect an altar to the Lord on that site (v. 18). When David went to build the altar and make the sacrifice, he was presented with what seemed like a great deal. Araunah offered to freely give him both the land for the altar and the oxen for the sacrifice. But David rejected his offer. How could he make a sacrifice that cost him nothing? The two were incompatible.
Too often when it comes to sacrifice, Christians are looking for a bargain. We want the most sacrifice for the least expense. We want lots of gain but little pain. Yet such a combination simply isn't possible. A sacrifice is only worth what you pay for it.
Don't go looking for sacrifices at a discount. God will have no cheap sacrifices. Be willing to pay the full price if you want the full benefit.
If it isn't a sacrifice to you, it isn't a sacrifice for you.