“Circumcise the foreskins of your hearts”
Circumcise yourselves to the LORD, and remove the foreskins of your hearts, O men of Judah and people of Jerusalem. (Jeremiah 4:4 BSB)
What it sounds like today
A jarring, almost crude physical image.
The cultural key
The metaphor startles modern readers, but it works precisely because circumcision was Israel's defining covenant sign, the mark cut in the flesh that said 'we belong to the LORD.' Jeremiah presses that the sign is empty if the heart is untouched, so he demands the real thing: 'remove the foreskins of your hearts,' cut away the thick, insensitive covering, the stubbornness and impurity, that keeps the inner self hard and unresponsive to God. It is a call to let the covenant reach past the body to the will and affections. Moses had already commanded it ('circumcise your hearts,' Deuteronomy 10:16), and Paul carries it into the New Testament: 'circumcision is of the heart, by the Spirit' (Romans 2:29). The physical image, far from crude, is a vivid demand that outward religion become inward reality, otherwise, Jeremiah warns, 'My wrath will break out like fire.'
Recovered meaning
'Circumcise the foreskins of your hearts' takes Israel's covenant sign inward: cut away the hard, stubborn covering over the inner self so the heart is responsive to God. The outward mark of belonging is worthless without this inner devotion.