Or has that part been excised out your bible?
1 John 1:7-10 But if we walk in the light, as he is in the light, we have fellowship with one another, and the blood of Jesus his Son cleanses us from all sin. If we say we have no sin, we deceive ourselves, and the truth is not in us. If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness. If we say we have not sinned, we make him a liar, and his word is not in us.
So what right does the priest have to retain sin that God promised would be forgiven if confessed? The priest certainly cannot read minds or know another person's heart.