This is not the throne but the floor beneath it. They saw the place where G-d was. Explain why some rabbis boasted of counting bricks during prayer. Rejoice with the Torah. Covenants include the appearance of G-d.
Spirituality flows from Torah study.
A proof to this is that they saw the work of sapphire, not natural, but man made sapphire tiles, the work of human hands. We eat and drink as a sign of dedicating our physical work to G-d.