The overall lesson of Numbers 12 is not to lift yourself up above or at the expense of others. Miriam and Aaron presumed that their younger brother, Moses, had the same type of relationship with God as they enjoyed and complained that he was ruler over them. They had no idea how intimately God spoke with Moses until now.
This passage is the pinnacle of Solomon as a messianic figure. In the first part of the chapter, we are introduced to the Queen of Sheba. She had heard of Solomon’s wisdom and recognized a supernatural source of Solomon’s wisdom.
Then the passage shifts to talk of silver. The people of Yerushalayim (Jerusalem) didn’t find any value for silver because symbolically they already were living in the messianic reign, but those in the nations, such as Egypt, symbolically were still longing for the word of God. They were longing for God’s teaching and counsel, just as the Queen of Sheba sought out Solomon’s.