Proverbs 17:26 - Matthew Poole's English Annotations on the Holy Bible

Also: this particle seems to have relation to the next foregoing proverb, to imply that it is a very evil thing for children to cause grief to their parents, as it is also to do what here follows. To punish the just; for parents, or princes, or rulers, to whom alone this power belongs, to punish innocent and good men; is not good; is highly evil and abominable, as is implied. See above, Proverbs 17:20, Proverbs 16:29 17:10, &c. Nor to strike princes for equity; nor to smite magistrates, either with the hand or tongue, for the execution of justice, as condemned persons are apt to do. Or, as some learned interpreters render it, nor for princes to strike any man for equity, or for doing his duty, or what is just. So this clause best agrees with the former. Besides, it belongs to princes or ms, strafes to punish or strike.