If an iron axhead ¹  is blunt and a workman ²  does not sharpen ³  its edge, ⁴  he must exert a great deal of effort; ⁵  so wisdom has the advantage of giving success.

“When that time comes, people will no longer say, ‘The parents have eaten sour grapes, but the children’s teeth have grown numb.’ ¹ 

Rather, each person will die for his own sins. The teeth of the person who eats the sour grapes will themselves grow numb. ¹ 

“What do you mean by quoting this proverb concerning the land of Israel, “‘The fathers eat sour grapes And the children’s teeth become numb?’ ¹