2 Samuel 22:31

As for God, his way is perfect; the word of the LORD is tried: he is a buckler to all them that trust in him.

This is part of a song David composed while Saul was pursuing and hunting him to take his life. He wrote it amid severe trials in which he was repeatedly preserved by special divine intervention. The song expresses his trust in God through those trials and praises God as his merciful preserver and deliverer.

Its teaching is that God's way is perfect, His word is tried and trustworthy, and He is a shield or buckler to everyone who trusts in Him.