From Dr. John Gill’s Exposition:
“Blessed are the pure in heart,.... Not in the head; for men may have pure notions and impure hearts; not in the hand, or action, or in outward conversation only; so the Pharisees were outwardly righteous before men, but inwardly full of impurity; but “in heart”. The heart of man is naturally unclean; nor is it in the power of man to make it clean, or to be pure from his sin; nor is any man in this life, in such sense, so pure in heart, as to be entirely free from sin. This is only true of Christ, angels, and glorified saints: but such may be said to be so, who, though they have sin dwelling in them, are justified from all sin, by the righteousness of Christ, and are “clean through the word”, or sentence of justification pronounced upon them, on the account of that righteousness; whose iniquities are all of them forgiven, and whose hearts are sprinkled with the blood of Jesus, which cleanses from all sin; and who have the grace of God wrought in their hearts, which, though as yet imperfect, it is entirely pure; there is not the least spot or stain of sin in it: and such souls as they are in love with, so they most earnestly desire after more purity of heart, lip, life, and conversation. And happy they are,
“for they shall see God; in this life, enjoying communion with him, both in private and public, in the several duties of religion, in the house and ordinances of God; where they often behold his beauty, see his power and his glory, and taste, and know, that he is good and gracious: and in the other world, where they shall see God in Christ, with the eyes of their understanding; and God incarnate, with the eyes of their bodies, after the resurrection; which sight of Christ, and God in Christ, will be unspeakably glorious, desirable, delightful, and satisfying; it will be free from all darkness and error, and from all interruption; it will be an appropriating and transforming one, and will last for ever.”
Monsignor Pope Ping!
Or perhaps, “cleansed” (we get our modern word “cathartic” from “katharos”).
A heartful of spiritual dirt makes it harder to appreciate the Lord.
I believe your post to be a good and accurate exposition of Matt 5:8 particularly in light of 1 Pe 1:22, 1 Tim 1:5 ans 2 Tim 2:22. I would add that a simplicity of heart involves a simple object of affection and obedience. That simple or singular object is Christ alone. That does not mean that Christ or the doctrine of Christ is for the simpleton, but that one's affections are not divided. An impure heart has other objects of worship that compete for the affections and the rule of the heart. Blessed are those who do not give power over their heart to any other than Christ, their single object of worship.