This beatitude is popularly understood as referring to chastity and to the keeping of the 6th Commandment. The expression “pure in heart” may imply chastity but that is not its primary meaning in the beatitude. Purity of heart is not the ritual and cultic purity required of the worshiping community of Israel. The external and the ritualistic purity of the Scribes and Pharisees of Jesus’ time do not indicate purity of heart. Their insistence on ritual and external purity was severely criticized by Jesus (Cf. Mt 15: 1-20; 23: 24-28). The purity of heart that Jesus mentions in the beatitude is not ritualistic but ethical purity. As we read in Psalms 15 and 24, it is this purity that is required of those who will ascend the mountain of the Lord and dwell in his presence. “Who shall ascend the hill of the Lord? And who shall stand in his holy place? He who has clean hands and a pure heart, who does not lift up his soul to what is false and does not swear deceitfully” (Ps 24: 3-4). The same idea is also expressed in Psalm 15: “O Lord, who shall sojourn in thy tent? Who shall dwell on thy holy hill? He who walks blamelessly and does what is right and speaks truth from his heart… (Ps 15: 1-2). In Psalm 73: 1 the pure in heart and the upright are equated by means of parallelism: “Truly God is good to the upright, to those who are pure in heart.”
In the Psalms “purity of heart” is not external, ritualistic or cultic purity but uprightness and truthfulness. The pure in heart then are those who are upright and blameless before God, who have no evil motives and who are sincere and truthful in their dealings with others. Such people, Jesus says, will see God. It means that when the fullness of salvation is revealed at the end of time, they will “see God as he is,” and experience peace, joy and intimate communion with God. It must be added that the pure in heart already experience the vision of God in and through Jesus. Nevertheless, Jesus’ promise is for the future when they will have the perfect vision of God, and see God “face to face” (1 Cor 13: 12).