Together with obedience also belongs the standing up for what you believe. The author will tell the glad news, as worded in Psalm 40:5, about the great wondrous deeds of the Lord, to the people in the great congregation. As many people as possible will be told about this. It concerns all the people of God, as Psalm 111:1 reads, “I will give thanks to the Lord with my whole heart, in the company of the upright, in the congregation.” In the form of a litotes—a figure of speech used to express an affirmative by denying its opposite—(also in Psalm 40:10), the author underlines his eagerness. I have not restrained my lips, as you know, O Lord.
I am true in word and deed.
This is in line with the king’s law of Deuteronomy 17:14–20. A king, who is obedient to God, is a blessing for the people; that is often the topic in Proverbs (e.g., Proverbs 14:34–35, Proverbs 16:12–13, Proverbs 20:8, Proverbs 20:26, Proverbs 20:28).
In Christ, we find the deepening of the gospel message, the glad news, as we learn in Romans 3:21–22: But now the righteousness of God has been manifested apart from the law, although the Law and the Prophets bear witness to it—the righteousness of God through faith in Jesus Christ for all who believe.
9 I have told the glad news of deliverance in the great congregation; behold, I have not restrained my lips, as you know, O LORD.