Psalm 119:43 And take not the word of truth utterly out of my mouth, for my hope is in your rules.
Here, David begs God not to take the word of truth out of his mouth. The Word of Truth is about God's faithful love and saving grace. If the Lord had not saved him, it would have meant that this word had been ripped out from his mouth, because it would no longer be true. The good thing is that God saves in accordance with His good and true word which is the gospel of the Kingdom of God.
Maybe we can understand this humble prayer from David, as a prayer to have a tongue of a disciple, which always has God's good word on the tongue at the right time. The prophet Isaiah said that God had given him a tongue of a disciple so that he could strengthen the faithful with one word (Isa. 50: 4). It is something of the best I know, when friends speak a word of God to me at the right time, just when I need to hear that word. Therefore I pray that I myself must not be empty of the word of God, but that I can always have a good word from God on the tongue. When we love the Word of God, we can bring forth new and old from the treasures of the Bible.
I also pray for boldness to say what God says in his word, and not be cowardly or afraid to face resistance. God said to Jeremiah: Do not be afraid of your opponents, or I will strike you with fear of them (Jer. 1:17). Fear of people makes us prisoners. Fear of others is tearing the word of truth out of our mouths. We must never be ashamed of God's word, for it is a word of truth.
I pray; do not remove the word of truth from my mouth, for to your judgments I have put my hope. I have put my hope in what God has determined. I bet everything that God's judgments are good and right. I have confidence in the way God judges and decides in the various cases. I wait in rest on what God has decided, the judgments and promises He has given, to be fulfilled before the eyes of all. I know that no one who waits for the Lord is disappointed or put to shame.
"May I never gloss over your truths, for I trust and depend on your principled decisions."