WASHINGTON — It was an interim ruling, and the majority gave no reasons. But the Supreme Court’s order on Friday night maintaining the availability of a commonly used abortion pill nonetheless sent a powerful message from a chastened court.

“Legal sanity prevailed, proving that, at least for now, disrupting the national market for an F.D.A.-approved drug is a bridge too far, even for this court,” said David S. Cohen, a law professor at Drexel University.

Ten months ago, five conservative justices overturned Roe v. Wade, eliminating a constitutional right to abortion that had been in place for half a century. They did so almost as soon as a third Trump appointee arrived, tilting the balance on the bench sharply to the right. All three of the Trump justices were in the majority.

Cynics might be forgiven for thinking that the decision last June, in Dobbs v. Jackson Women’s Health Organization, was a product of raw power. The public reaction was certainly negative, as the court’s approval ratings sank and the decision itself proved deeply unpopular and a political windfall for Democrats.

In his concurrence in Dobbs, Chief Justice John G. Roberts Jr. said the majority had abandoned “principles of judicial restraint” at the cost of “a serious jolt to the legal system.” Friday’s order avoided a second jolt.

But the Dobbs decision also made a kind of promise. The majority opinion, written by Justice Samuel A. Alito Jr., said at least seven times that doing away with the right to abortion was an exercise of judicial modesty.

“The authority to regulate abortion must be returned to the people and their elected representatives,” Justice Alito wrote, in a formulation that, with only small variations, was sprinkled throughout the opinion like a refrain.

Friday’s order, for the time being at least, vindicated that promise. The court blocked a sweeping ruling from Matthew J. Kacsmaryk, a federal judge in Texas appointed by President Donald J. Trump more noted for his anti-abortion bona fides than his legal acumen.

His ruling, based on judicial second-guessing of the many scientific studies buttressing the Food and Drug Administration’s approval and regulation of the pill, would have upended a status quo in place for 23 years.

Nor did the justices accept, for now, a less assertive alternative from a divided three-judge panel of the U.S. Court of Appeals for the Fifth Circuit. The majority, made up of two Trump appointees, would have sharply curtailed but not eliminated the availability of the pill.

Since the court took up the case on an expedited basis, on its so-called shadow docket, the justices could dissent without saying so publicly, making counting the votes an inexact science. On the available evidence, though, the vote on Friday night appeared to be 7 to 2.

It is all but certain that the court’s three liberal members — Justices Sonia Sotomayor, Elena Kagan and Ketanji Brown Jackson — were in the majority. It is a very good bet that Chief Justice Roberts, who staked out a compromise position in Dobbs, was with them.

And none of the members of the court appointed by Mr. Trump — Justices Neil M. Gorsuch, Brett M. Kavanaugh and Amy Coney Barrett — noted a dissent.

That left two justices. One, Justice Clarence Thomas, voted to allow the restrictions on the pill imposed by the Fifth Circuit but gave no reasons.

The other was Justice Alito, the author of the majority opinion in Dobbs. Notwithstanding his pledges that the court was getting out of the abortion business, he issued a dissent that packed a lot of grievance into its roughly three pages.

That was “very ironic and not at all surprising,” said Greer Donley, a law professor at the University of Pittsburgh and an author, with Professor Cohen and Rachel Rebouché, dean of Temple University Beasley School of Law, of “Abortion Pills,” an article to be published in The Stanford Law Review.

“Justice Alito, who wrote so passionately about returning abortion to the states to be decided by their elected representatives, would have allowed an order to take effect that made abortion less accessible only in states where abortion remained legal,” Professor Donley said.

Soon after the Biden administration and Danco Laboratories, which manufactures the pill, filed emergency applications on April 14 asking the Supreme Court to intervene, Justice Alito, who oversees the Fifth Circuit, paused Judge Kacsmaryk’s ruling for five days, until Wednesday. When that deadline arrived, he paused it for a second time, until Friday.

It is not clear how the justices spent the week, as it yielded only one opinion, the dissent from Justice Alito. He devoted much of it to accusing the Biden administration of acting in bad faith.

Justice Alito said, for instance, that the administration should have appealed a decision affirming abortion pill access from Judge Thomas O. Rice, a federal judge in Washington State appointed by President Barack Obama. Judge Rice’s decision was in tension with the one from Judge Kacsmaryk, blocking the F.D.A. from limiting the availability of mifepristone in much of the country.

Leah Litman, a law professor at the University of Michigan, said she found Justice Alito’s critique curious. If there was questionable conduct, she said, it was in the Texas litigation, as the lead plaintiff, a coalition of anti-abortion groups known as the Alliance for Hippocratic Medicine, had taken steps to ensure that the case would appear before a friendly judge.

“It was remarkable that Alito accused the federal government of bad faith in this matter for choosing not to appeal the initial order in the Washington case,” Professor Litman said, “when the plaintiffs in the Texas case incorporated in Amarillo so they could select Judge Kacsmaryk as the one to hear their request for a nationwide medication abortion ban.”

Justice Alito added that Danco, the pill’s manufacturer, would have had nothing to fear had the Supreme Court curtailed the F.D.A.’s approval of the drug while the case moved forward because, he said, the Biden administration would most likely have ignored the court’s ruling.

“The government,” Justice Alito wrote, “has not dispelled legitimate doubts that it would even obey an unfavorable order in these cases, much less that it would choose to take enforcement actions to which it has strong objections.”

Professor Litman said the dissent sounded more like a political argument than a legal one. “It just generally reads like an old guy who watches a lot of Fox News and is ranting about how he had to pay for a blue check mark,” she said.

The case now returns to the Fifth Circuit, which will hear arguments on May 17. After it rules, the losing side will almost certainly appeal to the Supreme Court, and the justices would then have another chance to decide whether to weigh in.

It would be a mistake to read Friday’s order as a definitive prediction of where they are headed. But there are reasons to think that an ambitious court has grown cautious.