Sometimes we think that circumcision was really only something that the Jews practiced, but if you go into the British Museum, you'll see that circumcision was a very common practice throughout the ancient Near East. It was a practice that was mainly associated with dealing with fertility issues, making it possible to have more children by removing the barrier between husband and wife, removing the foreskin. But the Lord calls his people to circumcise their hearts because this is the symbol of his covenant with them, the covenant he gave to Abraham to circumcise himself and to circumcise his sons and every male servant in his household as a sign of his loyalty to the great king, the Lord. And God's people, though, like all of us, would grow insensitive to the Lord, would create barriers in their relationship with the Lord, and so the Lord reminds them to remove those barriers, to re-sensitize their hearts in order to have fruitful lives under his reign. And so, in Deuteronomy 10, we see God in the giving of the law as they go into the land say, "circumcise your hearts." And then in Deuteronomy 30, at the end of this covenant ceremony, we see the Lord remind them again to live lives where they're constantly removing the barriers between them and the Lord and wanting to be fruitful in their life in the land. But it's interesting, Deuteronomy 30 sort of foreshadows something that's going to come, and that is that God's people will fall away from the Lord, and they'll have to be removed from the land. And yet the Lord says, "I will circumcise your hearts." There's this shift in Deuteronomy 30 from their responsibility to do that in their daily lives and yet that the Lord will do that for them as well. And we see that even in the new covenant that God will put his Spirit in our hearts, give us a new heart, a sensitive heart of flesh, and remove the heart of stone. So, the language of circumcision is a very strong reminder of the covenant sign and also of the situation we face as human beings that we need to constantly tend to our hearts before God, removing those obstacles, so that we can live fruitful lives as God's people.