Exodus 25:21-22

The top or the lid, called the mercy seat, served two purposes. The first is it was the lid for the chest. In chapter 31, a confirmation of something.

What Paul does here is associate the throne of grace with mercy. The inference is beginning to become quite obvious. The mercy seat and the throne of grace are one and the same thing. The mercy seat is the place from which God governs. That is, God judges. If we can think of this symbolically and try to put it into a literal context, we might say that God sits on the Ten Commandments. They are directly under Him. That place is symbolic of both judgment and mercy being dispensed from the very seat of God's government. The basis of both judgment and mercy are the Ten Commandments.

I did not say that those were the only factors that are included in judgment and mercy. I am saying that because of the symbolism that is given to us, we can understand God's law, which provides, as it were, a foundation underneath His judgments. Whether it be a merciful judgment in the sense of extending grace to someone, or whether it is a judgment in which extends a great deal of pain upon someone, the basis of that judgment is going to be the Ten Commandments.

Exodus 25:20-22

The mercy seat represented, symbolically, God's throne—the place where He sits and reigns over all that He has created.

The author of Hebrews here associates the throne of grace with mercy and the inference is obvious. The mercy seat and the throne of grace are one and the same. The mercy seat is that place, symbolically, from which God governs and judges. That is why the ark and its seat were shown in Revelation 11:19. God is shown symbolically sitting on the Ten Commandments. They are the legal basis of His judgments. The place is symbolic then of judgment and mercy being dispensed from the seat of God's government.

Exodus 25:21-22

There we see a synopsis of what the mercy seat and the ark are all about. The mercy seat was on top of the ark, which contained the law, an omer of manna and Aaron's rod, which established two things: The manna symbolized God's providence and grace; and the rod of Aaron symbolized the authority of the priesthood.

So you had those three things, and God sat on them, and judged, decreed, and commanded from there. All of these are symbolic. But, it was the Shekinah—God's visible presence—that rested above the mercy seat between the Cherubim. It was God's throne, as it were.