I wonder if forty days is some sort of significance. For Noah, God made it rain for forty days and nights. Jesus later is in the desert for forty days and nights. And then I believe it was forty days between Jesus' resurrection and ascension. I'm sure somewhere in between there are more references.
Moses was going to talk to God and obtain stone tablets that the commandments were written on. The Israelites saw Moses heading up to an all consuming fire on the mountaintop. I bet they were afraid and their fear will get the better of them.
Lord, I pray as I continue on the journey you have set out for me that I am not afraid and will not let fear consume me. If I see your powers before me, help me to see I have no reason to fear. Amen.