A spokesman for Alabama Republican Senate candidate Roy Moore’s campaign on Tuesday appeared dumbfounded when asked whether he knew that there is no legal requirement for elected officials to be sworn in using a Christian bible.

“Judge Moore has also said that he doesn’t think a Muslim member of Congress should be allowed to be in Congress. Why? Under what provision of the Constitution?” CNN’s Jake Tapper asked Moore spokesman Ted Crockett.

Moore in 2006 said that Rep. Keith Ellison (D-MN), the first Muslim elected to Congress, should not be sworn in because Moore claimed the Quran was not compatible with the Constitution.

“Because you have to swear on the Bible,” Crockett responded. “You have to swear on a Bible to be an elected official in the United States of America. He alleges that a Muslim cannot do that ethically, swearing on the Bible.”

“You don’t actually have to swear on a Christian Bible. You can swear on anything, really. I don’t know if you knew that. You can swear on a Jewish Bible,” Tapper said. “The law is not that you have to swear on a Christian Bible.”

Crockett fell silent for several seconds.

“You don’t know that?” Tapper added.

Crockett remained silent for several more seconds, then said, “I know that Donald Trump did it, when we made him President.”

“Because he’s Christian and he picked it,” Tapper replied. “That’s what he wanted to swear in on.”