Joe Biden’s former chief of staff, Ron Klain, also criticized the president.
“He signed Bibles with the same hand he used -- as president -- to sign hush money checks to an adult filmstar,” Klain said.
Politicos on Twitter likewise reacted with fury after several victims of the devastating tornado that touched down in Alabama last week asked Trump to sign their Bible. And he abided.
“Donald J. Trump is signing Bibles,” Peter Daou, a former adviser to Hillary Clinton and John Kerry, wrote on Twitter. “The man whose vicious and inhumane border policy violates the fundamental teachings of Jesus is signing Bibles.”
Yet, presidents have a long history of signing Bibles, including Barack Obama. Former presidents George W. Bush and Ronald Reagan also signed Bibles.
“Presidents seem to sign a lot of random things put in front of them,” Peter Manseau, the Smithsonian’s curator of religion, told the Washington Post.
Trump visited Alabama on Friday to survey the devastation and pay respects to tornado victims. The tornado carved a path of destruction nearly a mile wide, killing 23 people, including four children and a couple in their 80s, with 10 victims belonging to a single extended family.
At the Providence Baptist Church in Smiths Station, Ala., the Rev. Rusty Sowell said, the president's visit was uplifting and will help bring attention to a community that will need a long time to recover.
Before leaving the church, Trump posed for a photograph with a fifth-grade volunteer and signed the child's Bible, said Ada Ingram, a local volunteer. The president also signed her sister's Bible, Ingram said. In photos from the visit, Trump is shown signing the cover of a Bible.
And he was heavily criticized for it.
“People don't understand the purpose of Trump signing Bibles,” said one person. “May people are without a way to prepare food after a disaster. When Trump signs a Bible, its bursts in flame and people can cook over it.”
But not everyone slammed Trump for it.
Bill Leonard, the founding dean and professor of divinity emeritus at the Wake Forest University School of Divinity in Winston-Salem, N.C., said it's important to remember that signing Bibles is an old tradition, particularly in southern churches.
"It would've been worse if he had said no because it would've seemed unkind, and this was at least one way he could show his concern along with his visit," he said. "In this setting, where tragedy has occurred and where he comes for this brief visit, we need to have some grace about that for these folks."
Trump should have at least signed inside in a less ostentatious way, said the Rev. Dr. Kevin Cassiday-Maloney.
"It just felt like hubris," said Cassiday-Maloney, pastor at the First Congregational United Church of Christ in Fargo, North Dakota. "It almost felt like a desecration of the holy book to put his signature on the front writ large, literally."
The Associated Press contributed to this report.