Deuteronómio 10:16 Comentario: Rashi, Ramban, Ibn Ezra & Sforno

ערלת לבבכם [YE SHALL CIRCUMCISE] THE FORESKIN OF YOUR HEART — This means: ye shall remove the closure and cover that is on your hearts, [which prevent My words gaining entrance to them] (cf. Rashi on Exodus 6:12 and Leviticus 19:23).

CIRCUMCISE THEREFORE THE FORESKIN OF YOUR HEART — that your heart be open to know the truth, not as you have done to this day, for the Eternal hath not given you a heart to know, and eyes to see, and ears to hear [unto this day].²⁵²Further, 29:3.

Circumsize the foreskin of your hearts by distancing yourselves from desires, which are as thick and as heavy as a foreskin. Perhaps the idiom also means: Purify your heart, so that it will understand the truth.