When the education superintendent of Oklahoma, Ryan Walters, ordered this year that every public school classroom in the state must have a Bible in the classroom, he didn’t mention any special requirements.

But bid specifications for the Bibles, released this week, contain several narrowly drawn and unusual details. They must, for example, include text of the Pledge of Allegiance, the U.S. Constitution and other historical documents not normally included in the Bible.

What Bible fits the bill? The country music star Lee Greenwood’s God Bless the U.S.A. Bible, which is endorsed by former President Donald J. Trump and costs $60, far above the average price for Bibles. Mr. Trump receives royalties from their sales; financial disclosure reports filed in August show he has made $300,000 from the Bible since endorsing it.

The specifications caught the eye of Oklahoma Watch, a nonprofit news organization, which first reported this week that the bid specs seemed tailored to steer the state’s selection toward one Bible. Among other requirements, the bid rules require King James Version Bibles that are bound by leather or leather-like material.

About 20 million copies of the Bible are sold each year in the United States, and some printed versions are available for under $5. But each copy of Mr. Greenwood’s Bible includes a handwritten version of the chorus of his song “God Bless the U.S.A.,” a frequent anthem at Trump rallies. It also includes copies of the Constitution, the Bill of Rights, the Declaration of Independence and the Pledge of Allegiance. And it is bound in brown leather.

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