Deuteronomy 30:6
And the LORD your God will circumcise your heart, and the heart of your seed, to love the LORD your God with all your heart, and with all your soul, that you may live.
Torrey's Topical Textbook—AKJV

Romans 2:29
But he is a Jew, which is one inwardly; and circumcision is that of the heart, in the spirit, and not in the letter; whose praise is not of men, but of God.
Torrey's Topical Textbook—AKJV