An atonement cover or ‘mercy seat’ KJV, of pure gold, was to be made to cover the ark, and it measured about three and three-quarters feet long and two and a quarter feet wide, Exodus 25:17 / Exodus 37:6.
Constable, in his commentary, says the following.
‘The Greek word used to translate ‘mercy seat’ here in the Septuagint (hilasterion) is another form of the word used to describe Jesus Christ as our propitiation in 1 John 2:2 (hilasmos). The mercy seat was for the Israelites, temporarily what Jesus Christ is for all people permanently: the place where God found satisfaction.’
Two cherubim made out of hammered gold would be placed at each end of the cover, Exodus 25:18 / Exodus 37:7-8, and they were to be made of one piece with the cover, Exodus 25:19.
The cherubim are to have their wings spread upward, overshadowing the cover with them and they are to face each other, looking toward the cover, Exodus 25:20 / Exodus 37:9. The wings of the two Cherubim possibly touched one another to form a complete covering. The uncertainty should not unduly trouble us, 1 Corinthians 13:12.
The cover was to be placed on top of the ark, and the tablets of the covenant law were to be placed within it, Exodus 25:21. Above the cover, between the two cherubim, is where God will meet with Moses and give him all His commands for the Israelites, Exodus 25:22.
God’s presence did not dwell inside the box, but remained over the Ark, in between the two Cherubim. God dwelt ‘in unapproachable light’, 1 Timothy 6:16 / Psalm 104:2. The high priest had to shield his eyes, because ‘no man shall see Me and live’, Exodus 33:20. This was where God met with Moses, Exodus 25:21-22 / Leviticus 16:14-15.
There was a cover on the Ark, known as the Mercy Seat, or Propitiation Cover. It was here that the blood of a goat was sprinkled by the high priest on the Day of Atonement, to appease God’s righteous anger, ‘propitiate’ for the sins of the people of Israel, Exodus 37:1-9.
Romans 3:24-25 tells us that there is redemption in Christ Jesus because God has set Him forth as propitiation, through faith in His blood. Christ has died, and the price is paid. To those who believe in Jesus Christ’s death for their sins, there is now mercy, not wrath, Romans 5:8-9.
The glory of the Lord filled the tabernacle on the day it was reared up and anointed, Exodus 40:9 / Exodus 40:18 / Exodus 40:34-35, exactly fourteen days short of one year since the Exodus from Egypt, Exodus 40:2 / Exodus 12:6 / Exodus 12:31.
The two cherubim on the Mercy Seat represented God’s glory, Hebrews 9:5. We are not told in great detail exactly what the Ark of the Covenant looked like. Some models show the cherubim kneeling. Other models show the cherubim standing.