A single word uttered from an open heart can do more for us than any amount of anxious babbling. There’s a lot of mental and emotional debris floating around us and within us that needs to be removed so we can see God clearly. Jesus reminds us that humility is our first posture in prayer, remembering that God is God and we are not.
One of the most ancient prayers we can pray is this: "Lord Jesus Christ, Son of God, have mercy on me (a sinner).” A simple prayer like this is meant for repetition so that it becomes like breathing, sinking down from lips to heart - your spirit prays even when your lips aren’t.