The theophany on Sinai is undoubtedly the climax of Old Testament revelation. God spoke to Abraham for a few minutes at a time, scattered across decades of Abraham's life. But He spoke to Moses all day long for weeks. Fifty-seven chapters of Scripture were given at Sinai; there is no comparable chunk of revelation all given at once until the life and ministry of Jesus Christ. Obviously this is extremely important. Exodus 19 answers some big questions: How did God come? Why did God come? What was His coming like? And it also answers the question of how Israel prepared for His coming, which is at the core of this passage. Israel got ready to meet God by consecrating themselves and not touching the holy mountain or their wives. In short, in this passage we see God's holiness and how it demands that we too be holy — but it also relativizes and overshadows our holiness, showing that however we consecrate ourselves, God's holiness is still deadly to us unless He makes a way for us to come into His presence.