The mouth of the righteous speaketh wisdom - That is, It is a characteristic of the righteous to speak “wise things;” not to utter folly. His conversation is serious, earnest, true, pure; and his words are faithful, kind, and just. This, as a part of human conduct, is one of the reasons why God will bless him with prosperity and length of days.
And his tongue talketh of judgment - That is, of just or righteous things. See Matthew 12:35.