Carson comments on his 1998 Andrews University commencement speech where he said that his personal theory is that Joseph built the pyramids to store grain.
It’s still my belief, yes…the pyramids were made in a way that they had hermetically sealed compartments….You would need that if you were trying to preserve grain for a long period of time.
His comments then:
Now all the archeologists think that they were made for the pharaohs’ graves. But, you know, it would have to be something awfully big if you stop and think about it. And I don’t think it’d just disappear over the course of time to store that much grain…And various of scientists have said, ‘Well, you know there were alien beings that came down and they have special knowledge and that’s how–‘ you know, it doesn’t require an alien being when God is with you.