Matthew 5:27Meaning & Commentary from the Church Fathers

After presenting the first commandment in its fullness and elevating it to the pinnacle of spiritual life, the Savior then moves sequentially to the second commandment, adhering to the traditional order established by the ancient law. Some might argue that this should be considered the third commandment, noting that the commandment "Thou shalt not kill" is not the first. The initial commandment states, "The Lord your God, the Lord is one." Given this, we might wonder why the Savior chose not to begin His teaching with this commandment. The reason is clear: had He started with the first commandment, He would have been compelled to elaborate on it extensively, which would have involved a deeper discussion of Himself. The timing was not right for a comprehensive revelation of His identity.

Adultery and fornication are distinct acts. Adultery refers to engaging in sinful relations with a woman who is married, while fornication involves engaging in sinful relations with an unmarried woman.

The Law states that you shall not kill, and furthermore, it commands you shall not commit adultery. By reinforcing the earlier commandment, it transitions to the next one, guiding the emotions of anger and placing boundaries on desires as well.

According to the understanding of the Holy Fathers, two powerful passions dwell in the human heart, tainted by sin, serving as the root of many sorrows faced by the fallen offspring of Adam. These are the passions of anger and the lust of the flesh. The first, if left unchecked, can take hold in one's heart, which was designed for loving one's neighbors, replacing that love with harmful hatred toward them. The latter, if not extinguished at its outset, risks transforming the heart of a Christian—made pure through baptism and consecrated by the Holy Spirit for genuine love of God and virtue—into a sanctuary for impure desires that corrupt both soul and body.

The Lord declares, “YOU HAVE HEARD,” that it is spoken to the angels, “DO NOT LOVE.” This forms the seventh commandment of God’s Law, delivered at Sinai, and recognized even from the earliest days of humanity. This divine prohibition was sufficient for the ancients to maintain the purity of their souls. For instance, the virtuous Joseph escaped from the dishonorable advances of Pentephrius's wife, preserving both his body and his spirit in righteousness. In contrast, the Pharisee could engage in wrongdoing not through actions but rather within his inner being, harboring destructive vice in his heart, all while perceiving himself as just before God.

In unveiling the essence of this beginning, the Lord intentionally addressed and corrected several misconceptions that had been integrated into the moral teachings of that period by the legal experts. These teachers often manipulated the meaning of the commandments according to their own desires. Therefore, He clarified the authentic interpretation of the sixth, seventh, and third commandments, dismissed the erroneous understanding of divorce and revenge, and refuted the misguided conclusion regarding the hatred of one’s enemies as gleaned from some of Moses’ laws. In doing so, the Lord illustrated how the law ought to be perceived and what attitude a citizen of the kingdom of heaven should nurture within themselves.

The commandment against adultery, as presented in Exodus 20:14, was interpreted by the religious leaders of Jesus’ time in a strictly superficial manner, focusing solely on the physical act. However, Christ extends this condemnation to include both fornication and lust. He emphasizes the necessity for individuals to exercise self-control against the temptations to sin that surround them. It is preferable, albeit challenging, to abstain from certain earthly pleasures in this life rather than face destruction in Gehenna in the life to come.

In this passage, the Lord associates the seventh commandment from the Decalogue, which instructs against adultery (Exodus 20:14), with the inner duty to maintain purity, urging believers to cleanse their hearts from any lustful yearnings and impure notions. Anyone who harbors such desires and thoughts is guilty of adultery in their heart.

You have heard it stated to the ancients, "Thou shalt not commit adultery." The Jewish teachers interpreted this commandment primarily to refer to physical adultery, while also allowing for various indulgences of the flesh. However, within the law of the new covenant, sin was addressed at its origin—in the heart. It condemned not only unlawful actions but also the very thoughts and desires of the flesh, including lustful glances. For anyone who gazes at a woman with such intent "has already committed adultery with her in his heart."

You shall not commit adultery. This command represents the seventh instruction of the Mosaic Law (Exodus 20:14), addressing solely the external action of the sin itself, similar to the explanation of the sixth commandment. By emphasizing this law, the Savior reveals that the sin of adultery encompasses not just the physical act but also the internal desire—looking at a woman with lustful intent. 'He who commits adultery in his heart with his wife agrees to the act, but is restrained from it by circumstance, timing, or the fear of civil repercussions' (Athanasius the Great). This perspective does not undermine the Law; rather, it fulfills it, as one who refrains from viewing their spouse with lust truly upholds the commandment against adultery.

The second illustration. It has been said to those of old, "You shall not commit adultery." However, I tell you that anyone who looks at a woman with lustful intent has already committed adultery with her in his heart. The seventh commandment of the Old Testament (Exodus 20:14), which addresses the act of adultery itself, is illuminated by the Lord to show that the sinful nature lies not just in the act but also in the lascivious desires that arise from an impure gaze, fueling passionate thoughts. “The Savior does not prohibit gazing at wives entirely, but He only forbids looking at them with lust; for he who delights in observing beautiful faces ignites within himself the spark of desire, ensnaring his soul, leading to harmful wishes" (St. John Chrysostom).