WASHINGTON – Supreme Court justices appeared united Tuesday as they picked apart prison rules in Arkansas that allow full Afros and mustaches, but no beards, in a case about a Muslim inmate’s claim that his religious beliefs require that he be allowed to keep a half-inch beard.

The court heard arguments in its first religious liberty case since the Hobby Lobby case bitterly divided the justices in June over whether family-owned corporations could mount religious objections to paying for women’s contraceptives under the health care overhaul.

There was no such division evident in the courtroom Tuesday as several justices were openly skeptical of arguments made by a lawyer for Arkansas in defense of the state’s no-beard policy, which has no exception for religious beliefs.

The state has a legitimate security interest in prohibiting beards because prisoners can hide items in them and change their appearance by shaving, Arkansas Deputy Attorney General David Curran said.

Justice Samuel Alito, sounding like the prosecutor he once was, suggested a simple solution to the concealment issue: Give the inmate a comb and instruct him to comb the beard. “If there’s anything in there, if there’s a SIM card in there or a revolver or anything else you think can be hidden in a 1/2-inch beard, a tiny revolver, it’ll fall out,” Alito said to laughter.

Curran agreed. “That sounds like something that could be done,” he said.

Justice Ruth Bader Ginsburg also elicited some agreement from the Arkansas lawyer when she said, “You have no comparable rule about hair on one’s head, where it seems more could be hidden than in the beard.”

But here Curran added that officials have a second concern, their belief that appearance can be changed more readily by shaving a beard. “The material difference there is our professional judgment is the disguise-related component of a beard and shaving that beard is more profound than one on the head,” he said.

He also addressed another question about safety, saying inmates are given tamper-resistant safety razors. The state initially claimed that an inmate at a county jail used a blade hidden in his beard to commit suicide, but later conceded that he used a razor provided by his jailers.

Tuesday’s case stems from 39-year-old Gregory Holt’s claim that he has a right to grow a beard under a federal law aimed at protecting prisoners’ religious rights. The law is similar to the Religious Freedom Restoration Act that the court said in a 5-4 outcome in late June could be invoked by business owners who object to paying for contraceptives.

This time around, the Obama administration, religious groups and atheists alike are supporting Holt, also known as Abdul Maalik Muhammad. More than 40 states allow inmates to keep beards.

Holt is serving a life sentence for a brutal assault on his girlfriend and is being held at a maximum security prison 80 miles southeast of Little Rock. His case first came to the court’s attention when he filed a handwritten plea to the court asking it to block enforcement of Arkansas’ no-beard rule.

Holt argued in court papers that his obligation to grow a beard comes from hadiths, accounts of the acts or statements of the Prophet Muhammad. In one statement attributed to the prophet, Muslims are commanded to “cut the mustaches short and leave the beard.”

Holt said he understands that statement to mean he should grow a full beard, but offered a half-inch beard as a compromise because California allows Muslim inmates to wear beards of that length.

Chief Justice John Roberts and Justice Antonin Scalia were among those on the bench who sounded frustrated with the limited nature of what they were being asked to decide.

“I don’t want to do these cases half-inch by half-inch,” Scalia said.

Roberts said the argument made on Holt’s behalf by Douglas Laycock, a religious liberty expert at the University of Virginia, avoided difficult issues about where to draw the line to accommodate religious freedom on the one hand and the state’s legitimate security needs, on the other.

But Laycock said the justices should wait for another case to tackle those questions, and he predicted that a case of an inmate wanting a full beard would be next.

Ginsburg suggested that case could come from the refusal of prison officials to allow a follower of Sikhism to wear a turban and not cut his hair.

“That may be. I don’t know what the evidence would show about Sikh hair wrapped in a turban,” Laycock said. “But that’s clearly a much more serious issue than what’s presented in this case.”

A decision is expected by late spring in Holt v. Hobbs, 13-6827.