(19.) The wisdom (wisdom generically) strengthens (a play between תאחז above and תעז here) to the wise more than ten persons who have been invested with power who are (emphatic) in a city. Powerful men in a city are hard to overcome, or get at; ten, the indefinite number, gives the idea of ‘ever so many.’
20 For there is not a just man upon earth, that doeth good, and sinneth not.
However, there is no single man on earth so right that he always does good, and never makes a wicked mistake.
(20.) For a man (a man, as a specimen of the race, which we have already seen is the meaning of this word standing alone without the article) there is not (for we have in this case אין, and not לא; thus the meaning is, ‘there is not a single man’) made right in the earth who does good and does not sin (i.e. ‘make wicked mistakes:’ hence, as no man is perfectly right, it would be unreasonable to expect a perfect result; thus the relevancy of verse 17 is apparent. If our right acts do not always succeed, it is but just, considering the many sins we all commit).
21 Also [¹]take no heed unto all words that are spoken; lest thou hear thy servant curse thee:
[¹] Hebrew give not thy heart.