Solomon
Proverbs 17:6ESV·traditional attribution

Grandchildren are the crown of the aged, and the glory of children is their fathers.

Matthew Henry Presbyterian @wholebiblehenry

They are so, that is, they should be so, and, if they conduct themselves worthily, they are so. 1. It is an honour to parents when they are old to leave children, and children's children, growing up, that tread in the steps of their virtues, and are likely to maintain and advance the reputation of their families.

John Gill Reformed Baptist @doctorgill

Children's children are the crown of old men,.... Ancient parents. Grandfathers with the Jews are called old men, as Buxtorf (d) observes. A numerous progeny was reckoned a great blessing to a man; to have his table surrounded with children, as olive plants; to be encircled with a large family was a crown of glory (e); and to live to see children's children, a large...

Jamieson-Fausset-Brown Reformed @jfbcommentary

Prolonged posterity is a blessing, its cutting off a curse (Pro 13:22; Psa 109:13-15), hence children may glory in virtuous ancestry.