|Duccio di Buoninsegna, “Christ Taking Leave of His Disciples”|
As He gives the Spirit, Christ says, “If you forgive the sins of any, they are forgiven them; if you retain the sins of any, they are retained” even though only one who is by nature God has the power and authority to forgive sinners for their sins. After all, who could rightly grant pardon to others for their transgression of the divine law, except the one who gave that law? You may, if you wish, see the point of my statement from human affairs. Who has the authority to alter the decrees of earthly kings, and who tries to set aside the orders issued by decree and will of the rulers except someone who is invested with royal honor and glory? Only such a person cannot be accused of breaking the law. Wise is the saying, “Whoever says to the king, ‘You are a law-breaker,’ is insolent.”* In what way, then, and in what sense did the Savior clothe His disciples with an honor that belongs to the divine nature alone? The Word, who is in the Father, could not miss the mark of what is fitting; He was quite right to do this. He thought it was fitting that they who already had the divine and royal Spirit within them also have the authority to forgive and retain the sins of whomever they want, since the Holy Spirit dwelling in them forgives and retains sins according to His own will, even though the deed may be accomplished through human beings.
Cyril of Alexandria, Commentary on John
* Job 34:18