Deuteronomy 10:16,17

Ver. 16, 17. Circumcise, therefore, the foreskin of your heart— The Targum of Jonathan renders this, Cast away, therefore, the folly of your heart; and the LXX, the hardness of your heart. Circumcision was an emblem of sanctification. See Genesis 17:11 and the Reflections at the end of that chapter. The exhortation of Moses may be thus paraphrased: "Think not that, to please God, external circumcision and observance of the ceremonies of the law will suffice. It is essentially necessary, that you should reform what is vicious in your affections, that you should cut off and cast away whatever may render your hearts ungrateful to the benefits, insensible of the chastisements, and disobedient to the laws of your God; who, though peculiarly your God, (ver. 17.) is still the God of all mankind: a most righteous judge; who will not connive at your sins because you are circumcised, nor be bribed by any sacrifices to overlook your wickedness: nor, on the contrary, will he reject those who serve him in sincerity, though they may not be Jews; for he regardeth not persons." See Acts 10:34. In one word, the sacred writer means to inculcate the necessity of that internal circumcision which St. Paul so strongly recommends, Romans 2:28. In the words, nor taketh reward, Moses seems to allude to the gifts which were offered by the princes for the building of the tabernacle; perhaps also to the victims and gifts of the sacrifices, which were never acceptable to him without love in the heart of the giver.