Matthew Henry on Exodus 25:10-22

The ark was a chest, overlaid with gold, in which the two tables of the law were to be kept. These tables are called the testimony; God in them testified his will. This law was a testimony to the Israelites, to direct them in their duty, and would be a testimony against them, if they transgressed. This ark was placed in the holy of holies; the blood of the sacrifices was sprinkled, and the incense burned, before it, by the high priest; and above it appeared the visible glory, which was the symbol of the Divine presence. This was a type of Christ in his sinless nature, which saw no corruption, in personal union with his Divine nature, atoning for our sins against it, by his death. The cherubim of gold looked one towards another, and both looked downward toward the ark. It denotes the angels' attendance on the Redeemer, their readiness to do his will, their presence in the assemblies of saints, and their desire to look into the mysteries of the gospel. It was covered with a covering of gold, called the mercy-seat. God is said to dwell, or sit between the cherubim, on the mercy-seat. There he would give his law, and hear supplicants, as a prince on his throne.