Proverbs 9:9

New English Translation

⁹Give instruction^[a] to a wise person,^[b] and he will become wiser still;
teach^[c] a righteous person and he will add to his^[d] learning.

Proverbs 9:9 tn Heb “Give to the wise.” The object, “instruction” (or possibly rebuke), is implied. Most translations either supply the object (NIV, NLT, Holman) or change the verb to “instruct” (NASB, ESV, NKJV, NRSV).
Proverbs 9:9 sn The parallelism shows what Proverbs will repeatedly stress, that the wise person is the righteous person.
Proverbs 9:9 tn The Hiphil verb normally means “to cause to know, make known,” but here the context suggests “to teach” (so many English versions).
Proverbs 9:9 tn The term “his” does not appear in the Hebrew text, but is supplied for the sake of smoothness and clarity.

New English Translation (NET)