In this verse, Apostle Paul derived the image of God, as a "consuming fire" from Exodus 24:17; Genesis 4:24 and Isaiah 33:14. The Israelites saw the glory of God as a fire on top of Mount Sinai (Exodus 24:17). The glory of God is the sign of His presence and it is a fire. (See also Exodus 40:34-35). To witnesses of these events, Moses, Aaron, Abihu, and others (Exodus 24:9-10), it looked as if God really was “a consuming fire", a fire destroying everything.
In Hebrews 12:29, Paul refers to the destruction in symbolic language of the sinful world order in the Day of Jehovah. Hebrews chapter 12 refers back to the inauguration of the Law Covenant at Sinai as an illustration of the inauguration of the New Covenant. With the start of Christ’s kingdom, the voice of God will shake the literal earth. In the typical event, God’s voice did shake the literal earth, but now God has promised more, saying: “Yet once more