"Heaven is my throne,
and the earth is my footstool.
Where is the house you will build for me?
Where will my resting place be?
and so they came into being?"
declares the LORD.
For the earth will be filled with the knowledge of the glory of the LORD,
as the waters cover the sea.
The whole temple needs to be filled. Who is supposed to fill this temple that God has made? Isaiah goes on to answer this question later in chapter 66, well the LORD does through Isaiah's words.
"I will set a sign among them, and I will send some of those who survive to the nations—to Tarshish, to the Libyans and Lydians (famous as archers), to Tubal and Greece, and to the distant islands that have not heard of my fame or seen my glory. They will proclaim my glory among the nations. And they will bring all your brothers, from all the nations, to my holy mountain in Jerusalem as an offering to the LORD -on horses, in chariots and wagons, and on mules and camels," says the LORD. "They will bring them, as the Israelites bring their grain offerings, to the temple of the LORD in ceremonially clean vessels. And I will select some of them also to be priests and Levites," says the LORD.