God’s main concern when he planned for the people of Judah to be taken into captivity was the condition of their hearts. The relationship God wanted to have with his people was one of love and trust. In order for that to be possible, the people had to be devoted to God and open to his involvement in their lives. The way Jeremiah described this was to use circumcision as an illustration of being dedicated to the LORD. He told the people, “Circumcise yourselves to the LORD, and take away the foreskins of your heart” (Jeremiah 4:4). Moses used similar language when he said, “Circumcise therefore the foreskins of your heart, and be no more stiffnecked” (Deuteronomy 10:16).
The Hebrew words translated stiffnecked, qashah oreph literally mean hard necked or a neck that is unable to bend and be bowed down as in prayer (7185/6203). Looking at this term in relation to the heart, it refers to someone who is hard-hearted, a tough minded person who refuses to submit himself to God. Therefore, to circumcise the heart would mean you cut off behavior that is offensive to God (4135). Jeremiah referred to the cleansing of the heart in connection with salvation. He said, “O Jerusalem, wash thine heart from wickedness, that thou mayest be saved” (Jeremiah 4:14). Typically, a person is only concerned with washing the exterior part of his body. Jeremiah was pointing out that it was the inner man that needed to be dealt with.