Purity of heart is not something to be attained or acquired, it is the removal of all that is impure or tumah in the heart. In order to have pure gold, the gold must go through the smelting process of heat to remove the impurities. When it is pure, it becomes clear and malleable.
"Your eyes will see Jerusalem: A tent which will not be folded; its stakes will never be pulled up" (Isaiah 33:20).
