“If any man's wife goes astray and breaks faith with him …” (v12). Similar to practices in other ancient cultures, an Israelite man who suspected his wife of unfaithfulness was supposed to bring her to the priest for a ritual that would expose the truth. The man offered a grain sacrifice and the woman drank dusty water, which would not harm her unless God Himself saw her guilt and pronounced judgment (v19). Without real evidence of her crime, no one was allowed to punish the woman except God.
Jesus warned against looking good before people but hiding sin, because we all stand exposed “before the Lord” (v30). He is the Judge who sees the heart.