Midrasch zu Mischlej 27:22

And the king answered and said unto the man of God: “Entreat now the favor of the Lord thy God, and pray for me” (ibid., v. 6). Two amoraim¹³Talmudic authorities who lived after the final redaction of the Mishnah. discussed this verse. One commented that he said thy God and not “my God.” The other retorted: How could he call Him “my God” while he stood and sacrificed before an idol whom he addressed as “my god”? Nevertheless The man of God entreated the Lord, and the king’s hand was restored, and became as it was before (ibid.). What is meant by as it was before? R. Judah the son of Simon began the discussion with the verse in the name of R. Joshua the son of Levi: Though thou brayest a fool in mortar with a pestle among groats, yet will not his foolishness depart from him (Prov. 27:22). That is to say, it will have no effect (on the fool, he learns nothing). Likewise he had previously sacrificed to an idol, and he did so again.

Solomon declared: Though thou shouldst pound a fool in a mortar with a pestle among groats, yet will not his foolishness depart from him (Prov. 27:22). This verse indicates that if one beats a fool, the fool forgets the first blow, even while the staff is suspended above his head for the second blow. And with a pestle among groats implies that as soon as the staff is raised, he has already forgotten the second blow. Hence, Yet will not his foolishness depart from him.

Similarly, the generation of the separation failed to learn from the experience of preceding generations. Hence it is written: Though thou shouldst pound a fool in a mortar with a pestle among groats, yet will not his foolishness depart (Prov. 27:22). What is meant by among groats (harifut)? This refers to the men of the generation of the separation, who blasphemed (m’harifin) the Unique One of the world.