When I studied the beatitudes in catechism class in parochial school, Sister always related the sixth beatitude to the Sixth Commandment. Purity of heart meant bodily purity and avoiding sins of the flesh.

When I studied the beatitudes in Scripture class in the seminary, the professor widened the vision by relating the sixth beatitude to Psalm 24. The psalmist asks, “Who may go up the mountain of the Lord? Who can stand in his holy place?” He answered the question with these words: “The clean of hand and pure of heart, who are not devoted to idols, who have not sworn falsely ... Such are the people that love the Lord, that seek the face of the God of Jacob.”

Psalm 24 taught that only one whose heart is clean can take part in temple worship in Jerusalem. To be with God in the temple is described in Psalm 42 as “beholding His face.” But in this sixth beatitude Jesus makes the promise to the pure and clean of heart that they will see God not in the man-made temple in Palestine but in the coming Kingdom.

We should note, however, that the criterion of purity or cleanliness of heart is the same for the psalmist and for Jesus; and we should note it well. The criterion for purity of heart is keeping all Ten Commandments with the help of grace, not just the sixth.