Deuteronomy — Chapter 18

Neither let there be found among thee any one that shall expiate his son or daughter, making them to pass through the fire, or that consulteth soothsayers, or observeth dreams and omens, nor a wizard, nor a charmer, nor any one that consulteth pythonic spirits. All divination, astrology, necromancy, and magic are absolutely forbidden, because they involve either fraud or compact with demons. Only prophets—true messengers of God—are to be heard.

Thou shalt be perfect, and without spot with the Lord thy God. To love and obey God alone, avoiding all idolatrous rites, is the perfection God requires. Lapide quotes Cassian's ladder of perfection: from fear of God, to compunction, renunciation, humility, mortification of the will, extirpation of vices, growth of virtues, purity of heart, and finally the perfection of apostolic charity.

The Lord thy God will raise up to thee a prophet of thy nation and of thy brethren like unto me: him thou shalt hear. Lapide: This text has a twofold literal sense. The first and proximate sense refers to the succession of true prophets whom God would send to Israel until the time of Christ. The principal and highest sense refers directly to Christ Himself, as is clear from Acts 3:22 and Acts 7:37. Moses as Prophet is a type of Christ: as Moses led the people out of Egypt, Christ redeems men from servitude to sin; as Moses led to Canaan, Christ leads to heaven; as Moses worked great miracles, so did Christ; as God spoke to Moses face to face, so Christ is the Word of God intimately united to the Father.

I will raise them up a prophet out of the midst of their brethren like to thee: and I will put my words in his mouth. God places His own words in the Prophet's mouth, making Him the perfect interpreter of the divine will. Lapide cites St. Cyprian's golden summary of what Christ taught and did: humility in His Incarnation, constancy in faith, modesty in speech, justice in works, mercy in deeds, discipline in morals, and steadfastness in suffering unto death.

And he that will not hear his words, which he shall speak in my name, I will be the revenger. To reject the Prophet (Christ) is to invite divine vengeance. Lapide applies this to those who reject Christ's doctrine and Church, warning that the Redeemer becomes the Judge of those who spurn His grace.