Nearly seven years since he last spoke up during oral arguments, Justice Clarence Thomas cracked a joke today. Unfortunately, it's unclear exactly what he said.

Years of Silence for Supreme Court Justice

The comment came during a Sixth Amendment case brought by Jonathan Boyer, who was convicted of murder.

At one point, according to the transcript, the justices began discussing the qualifications of the lawyers who had assisted Boyer.

Justice Antonin Scalia asked Carla S. Sigler, the assistant district attorney of Louisiana, about one of the lawyers.

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"She was a graduate of Yale Law School?" Scalia asked.

Sigler responded, "She's a very impressive attorney."

Then Scalia talked about another lawyer, who is a graduate of Harvard Law School.

"Son of a gun!" joked Scalia, a Harvard Law graduate himself (1960).

The court transcript shows Thomas piping in at that point. But all the transcript reveals is:

"JUSTICE THOMAS: Well - he did not - (Laughter.)"

The court reporter was unable to transcribe the words because of the laughter in court.

A lawyer who was present in court told ABC News that Thomas, who graduated from Yale Law School, was making a joke about Harvard Law School.

But SCOTUS BLOG, the popular blog dedicated to the Supreme Court, sent out a tweet suggesting that the justice was poking fun at his alma mater: "@SCOTUSblog Thomas, J. speaks: funny at argument-Yale degree could mean lawyer is incompetent, not competent, capital trial counsel."

The Associated Press' excellent reporter Mark Sherman wrote in his dispatch: "What Thomas said is not clear, other than he appears to have joked about Ivy League lawyers."

Thomas (Yale, '74) has had a strained relationship at times with his former school.

"Yale meant one thing for white graduates and another for blacks," Thomas wrote in his 2007 book, "My Grandfather's Son."

Thomas, 64, says in the book that after he graduated, "As a symbol of my disillusionment, I peeled a fifteen cent price sticker off of a package of cigars and stuck it on the frame of my law degree to remind myself of the mistake I'd made by going to Yale."

But, recently, he has had a closer relationship with the school. He was a guest speaker last year and also spoke at the Yale Law School Association's annual dinner in June.