Those priests work in a copy, like a shadow, of the real place in heaven. God told Moses, Make the tent like the plan I showed you on the mountain. ⛺️⛰️
The place where they serve is a copy and shadow of what is in heaven. This is why Moses was warned when he was about to build the tabernacle: “See to it that you make everything according to the pattern shown you on the mountain.”
KJV
Who serve unto the example and shadow of heavenly things, as Moses was admonished of God when he was about to make the tabernacle: for, See, saith he, [that] thou make all things according to the pattern shewed to thee in the mount.
ASV
who serve that which is a copy and shadow of the heavenly things, even as Moses is warned of God when he is about to make the tabernacle: for, See, saith he, that thou make all things according to the pattern that was showed thee in the mount.