Read Ex 25:10-22; 37:1-9
The only piece of furniture in the Most Holy (Holy of Holies) was the Ark of the Covenant.
The ark was a chest like structure that the mercy seat sat upon, the mercy seat being the cover. Together they are referred to as the "Ark of the Covenant". The ark was made of acacia wood over laid with gold. It was 2 1/2 cubits long, 1 1/2 cubits wide, and 1 1/2 cubits high. It had a crown around the top to secure the mercy seat. The mercy seat was a solid gold lid on the top of the ark.
It had 2 golden cherubim one on each end. Their wings were stretched over the seat as they faced toward each other and down toward the mercy seat. They represented G-d's glory.
The "mercy seat" literally means "place of Atonement". It is so named because it was where G-d manifested Himself for the purpose of atonement.
The ark had 4 gold rings 2 on each side, probably near the base. They held the gold covered wooden poles used to carry the ark.
The ark contained 3 items:
The "Holy of Holies" was off limits to everyone. Entrance into it was allowed only once a year on Yom Kippur (the Day of Atonement), and was restricted to the High Priest himself.
The other furnishings required the priests to perform daily or weekly functions associated with them. They symbolized the various ministries of Yeshua.
Ex 37:3-5 - And he cast for it four rings of gold, to be set by the four corners of it; even two rings upon the one side of it, and two rings upon the other side of it. And he made staves of shittim wood, and overlaid them with gold. And he put the staves into the rings by the sides of the ark, to bear the ark.
The ark is a type of Yeshua HaMashiach. As G-d's perfect Son, and yet perfect man . The wood represents His humanity, and the gold both inside and outside the ark represent His deity. In Him dwelt the law of G-d perfectly (stone tables), the priesthood of G-d fully (Aaron's rod), and the bread of G-d abundantly (Manna). His is G-d's "mercy seat" place of atonement; G-d meets the sinner in Yeshua HaMashiach. Yeshua is called the "propitiation" in Romans 3:25 which is understood to be the same as the mercy seat. The expression "mercy seat" means "propitiatory" (atonement). We come to Yeshua, both as our High Priest and also as our "mercy seat", that we may confess our failures and receive again the cleansing of the precious blood. Mercy abounds there. Mercy meets the needs and requirements of justice.
The Ark had rings in the side, two to a side, to bear the ark. This symbolized Yeshua's hands and feet with the four holes that bore his body on the beam. The opening in the Ark represented the wound in His side. The Ark was also were judgment resided over Israel and the Priests had to make atonement for sin through the shedding of blood. In the same respect He is our judge and will judge all. The Ark's presence did no only come to Israel but to other nations such as the Philistines. This symbolized our L-rd not only coming to save the lost of the nation of Israel, but also to the lost of the Gentiles.
John 18:4-6 - "Jesus (Yeshua) therefore, knowing all things that should come upon him, went forth, and said unto them, Whom seek ye? They answered him, Yeshua. Yeshua saith unto them, I am he. And Judas also, which betrayed him, stood with them. As soon then as He had said unto them, I am he, they went backward, and fell to the ground."Here He declares He is the great "I am" and reminds us of the Philistines falling dead before the Ark. Ruach HaKodesh (G-d. the Holy Spirit) dwelt above the mercy seat.
The ark is discussed in greater detail in the study on the "Day of Atonement".