Then the LORD said to Moses, "Write down the words I have spoken… (Exodus 34:27a NIrV)
I've seen snakes before, but I've never seen a snake turn into a walking stick and vice versa.
I've seen illnesses, but I've never seen a skin disease appear and disappear on command.
I've seen blood, frogs, gnats and flies, but I've never seen them appear over many miles of land and water on command and disappear when told.
I've seen livestock, boils, and hailstorms before, but I've never seen them inflicted on one group of people while another group close by is completely protected...as predicted.
I've lived through large numbers of locusts, but not when someone called them upon me as a plague.
I've experienced complete darkness, but it was in a cave - not above ground.
I've experienced death, but not a plague of death only on firstborn sons of my enemy.
I've seen clouds of smoke rise into the sky, but I've never seen a pillar of smoke move on it's own to lead me.
I've never seen a pillar of fire.
I've enjoyed swimming in water, but I've never walked through water on dry ground while walls of water formed on either side of me until I was through safely...then crashed down on my enemies.
I've never experienced bitter water becoming drinkable in the desert.
I've never eaten bread-like flakes off of a desert floor.
I've never watched bread go bad in a day...except on the seventh day of the week.
I've never had birds fall into my camping trip for dinner...every night.
I've never had water that gushed through a rock in the middle of the desert.
There were eye witnesses to these things...over one million of them. They didn't turn back. They stayed with the leader who predicted these things and through whom these things were done. They followed him, even when it meant wandering in a desert for forty years. This leader said he did not have the power to do these things. God was doing them. He simply told them what God was going to do and why. After a while, they believed this leader. The miracles confirmed that he was hearing from God.
When this leader wrote down what God told him to write down, the people listened. They learned. They shared it with their children and their children's children. They preserved what was said. They wrote it down. These writings became known as the Pentateuch - the first five books of The Bible.
The leader was Moses.
The author was God.