God’s righteousness is what He does in fulfillment of the terms of the covenant that He established with His chosen people through Christ. The righteous person in the Bible is one who meets the demands of a variety of social relations (wife, children, family, friendship, city and nation, servants, foreigners) and has done righteousness before God in their covenant with him, though the requirements of righteousness varied within the covenantal/relational context.
Therefore, the tongue and lips of the righteous are choice silvers, nourishing many. If I want to be righteous I need to speak words of praise about God and be helpful and life-giving to others. Are there any words that I said yesterday that I should correct today? Did I speak God’s name in vain? Did I give him credit for what he’s done? Is there someone today that needs kind and uplifting words from me?
The heart of the wicked is of little value and thus their tongue and lips do not speak words fitting for a covenant with God and others. They are fools that die for lack of judgment. The heart is the control of the tongue. If I speak poor words then I need to ask God to enrich my soul through Jesus. Peter wrote, “If anyone speaks, he should do it as one speaking the very words of God.” (1 Peter 4:11)