A תלמיד חכם once explained the פסוק in משלי which states: בן חכם ישמח אב ובן כסיל תוגת אם. He asked: “What did שלמה המלך see to cause him to attribute the יחוס of the בן החכם to the father and the בן הכסיל to the mother, rather than the reverse? Our חכמים said ברא כרעא דאבוהי. The son’s traits are similar to those of his father. Therefore, a בן חכם is his father’s joy, since it shows that the father is also a חכם. But a בן כסיל shows that his father is also a כסיל. And this is a great sadness, תוגה גדולה, for the mother, who has two כסילים in the house.”
06/10/2021