Inside the Holy of Holies

"The command was communicated to Moses while in the mount with God, "Let them make Me a sanctuary; that I may dwell among them;" and full directions were given for the construction of the tabernacle. 

Beyond the inner veil was the holy of holies, where centered the symbolic service of atonement and intercession, and which formed the connecting link between heaven and earth. 

In this apartment was the ark, a chest of acacia wood, overlaid within and without with gold, and having a crown of gold about the top. It was made as a depository for the tables of stone, upon which God Himself had inscribed the Ten Commandments. 

--Hence it was called the ark of God's testament, or the ark of the covenant, since the Ten Commandments were the basis of the covenant made between God and Israel.
The cover of the sacred chest was called the mercy seat. This was

wrought of one solid piece of gold, and was surmounted by golden cherubim, one standing on each end. One wing of each angel was stretched forth on high, while the other was folded over the body (see Ezekiel 1:11 Thus were their faces: and their wings were stretched upward; two wings of every one were joined one to another, and two covered their bodies.) in token of reverence and humility. 

The position of the cherubim, with their faces turned toward each other, and looking reverently downward toward the ark, represented the reverence with which the heavenly host regard the law of God and their interest in the plan of redemption." 

E.G.W.