The word for ‘pure’ that Jesus uses here in the sixth beatitude means in Greek just what it means in English, as when we say, “Her heart was pure gold.” We mean that her essence is unalloyed, not contaminated with traces of zinc, iron, lead, or whatever it is that makes gold less than 24-karat. 

Her heart is unadulterated, free from any hint of other color or substance, untarnished by any fleck of stain. There is only one thing in there, and nothing else, nothing else at all. No alloys, additives, preservatives, contaminants; nothing shameful, nothing false, nothing unclean. She is like Dany Targaryen’s troops: The Unsullied.