2Sam 24:22

“Therefore, the king himself offered blessed David the threshing floor and oxen for a burnt offering, but King David refused to accept them without first paying a price. This, too, was fulfilled at the coming of our Lord and Savior, for he refused to take the hearts of the Gentiles for himself without first giving his precious blood for them. What, then, did he give? "Fifty shekels of silver," it says. In the number fifty the grace of the Holy Spirit is understood and the remission of sins is designated. Indeed, on the fiftieth day the Holy Spirit was sent to the apostles, and in the Old Testament the fiftieth year was dedicated to forgiveness and pardon. That David, to be sure, gave silver; our David, whose type the other prefigured, shed his precious blood. Thus, in order to buy the pagan king's threshing floor David offered fifty shekels; in order to build an altar to himself on the threshing floor of the Gentiles Christ, the true David, gave the grace of the Holy Spirit and forgiveness of sins on the fiftieth day. Therefore, brothers, since he has deigned to make a temple for himself in us and out of us, let him not suffer any insult in his home. If he does suffer injury because of our sins, he quickly withdraws, and woe to the unhappy soul from which he departs. Doubtless, if one is deserted by the light he will be seized by darkness. For this reason let us with his aid endeavor so to live that we may merit to have the good Lord not only as our guest but as a perpetual inhabitant: with the help of our same Lord Jesus Christ, to whom is honor and glory together with the Father and the Holy Spirit world without end. Amen.”