MIAMI  — Republican presidential candidate Ben Carson on Thursday stood by his belief that Egypt’s great pyramids were built by the Biblical figure Joseph to store grain — not as tombs for pharaohs.

Video posted online Wednesday by Buzzfeed News shows Carson explaining his theory 17 years ago at a Michigan college affiliated with his Seventh-day Adventist Church.

In the video, Carson says: “My own personal theory is that Joseph built the pyramids in order to store grain.” He was referring to the Old Testament story of Joseph predicting famine and advising the pharaoh to store surplus food. He said that’s more likely than the accepted archaeological conclusion that the massive structures were built as tombs for pharaohs.

At a book signing Thursday in Florida, Carson stood by his statement on the grain storage.

“Some people believe in the Bible like I do and don’t find that to be silly at all, and believe that God created the earth and don’t find that to be silly at all,” Carson said. “The secular progressives try to ridicule it every time it comes up and they’re welcome to do that.”