"When Brennan vowed to protect and defend the Constitution, he was swearing on one that did not include the First, Fourth, Fifth, or Sixth Amendments – or any of the other amendments now included in our Constitution," it said. "The Bill of Rights did not become part of our Constitution until 1791, four years after the Constitution that Brennan took his oath on."
https://www.christianpost.com/news/john-brennan-chooses-not-to-use-bible-for-swearing-in-as-cia-director-91633/