Exodus 25:22
And there I will meet with you, and I will commune with you from above the mercy seat, from between the two cherubim which are on the ark of the testimony, of all things which I will give you in commandment to the children of Israel.
Torrey's Topical Textbook—AKJV

Leviticus 16:2
And the LORD said to Moses, Speak to Aaron your brother, that he come not at all times into the holy place within the veil before the mercy seat, which is on the ark; that he die not: for I will appear in the cloud on the mercy seat.
Torrey's Topical Textbook—AKJV

Numbers 7:89
And when Moses was gone into the tabernacle of the congregation to speak with him, then he heard the voice of one speaking to him from off the mercy seat that was on the ark of testimony, from between the two cherubim: and he spoke to him.
Torrey's Topical Textbook—AKJV