Gr. kardia, “heart,” here referring to the intellect, the affections, and the will. As a man “thinketh in his heart, so is he” (Prov. 23:7). Christ points out that character is determined, not so much by the outward act, as by the inward attitude that motivates the act. The outward act merely reflects and activates the inward attitude. He who would commit a wrong act if he thought he could escape detection, and who is restrained only by that fear, is, in the sight of God, guilty. Sin is first and above all else an act of the higher powers of the mind—the reason, the power of choice, the will (see on Prov. 7:19). The outward act is merely an extension of the inward decision.

 Gr. epithumeō, “to set one’s heart upon [a thing],” “to long for,” “to covet,” “to desire.” “Lust” is an old Anglo-Saxon word meaning “pleasure,” “longing.” “To lust” for a thing is to experience an intense, eager desire for it. Epithumeō is used in both a good and an evil sense. Jesus told the Twelve that with “desire” (epithumia) He had “desired” (epithumeō) to eat the last Passover with them (Luke 22:15). In its good sense epithumeō appears also in Matt. 13:17; Luke 17:22; Heb. 6:11; 1 Peter 1:12; etc.).

 The related noun, epithumia, “desire,” is used similarly in Phil. 1:23; 1 Thess. 2:17.

 One of the Hebrew equivalents of epithumeō is chamad, “to desire,” “to take pleasure in.” Chamad is rendered “covet” in the tenth commandment (Ex. 20:17) and “desire” in Deut. 5:21 and Isa. 53:2. Christ was doubtless thinking of the tenth commandment when He warned against looking “on a woman to lust after her.” In other words, the man who orders his affections and his will in harmony with the tenth commandment is thereby protected against violating the seventh.

Feminine beauty is a gift from a loving Creator, who is a lover of all true beauty. The pure appreciation of that beauty is both right and proper. Furthermore, the attraction each sex has for the other was implanted within men and women by the Creator, and when operating within the limits ordained of God, is inherently good, but when perverted to serve selfish, evil interests, becomes one of the strongest destructive forces in the world.

 See on v. 22. Fundamentally, Jesus’ discussion of the marriage relationship and its responsibilities is based on God’s original plan for the home as stated in Gen. 2:21-24 (see Matt. 19:8) and not on the Mosaic law (see Deut. 24:1-4). In that plan, marriage was intended to meet the need for companionship (Gen. 2:18), and to provide a home and proper training for the children that would be born (see Gen. 1:28; 18:19; Prov. 22:6; Eph. 6:1-4). The home was thus established as an ideal environment in which both parents and children might learn of God and might develop characters that would measure up to the lofty ideals inherent in the divine purpose that led to their creation.