You are the salt of the earth.  You are a light on a lampstand.  Where does Jesus get this?  From the temple: Salt is added to the animal sacrifices, and in the Holy Place there are lights on lampstands.

Does he ever get into the Most Holy Place?  Yes: In Matthew 5:17-20, He speaks of His and the disciples’ relation to the law, to the tablets of the Torah that are in the ark.  In a sense, the entire sermon thereafter takes place in the Most Holy Place.