Supreme Court Justice Clarence Thomas, 75, sparked raised eyebrows over his whereabouts when he was absent during oral arguments on Monday, and the Court provided no explanation.

Chief Justice John Roberts addressed Thomas’ lack of presence, according to NBC News’ Lawrence Hurley, saying that Thomas “is not on the bench today” but would “participate fully” in the two cases being argued based on the briefs and transcripts.

“Context that may or may not be helpful: In the recent past, Justice Thomas phoned into oral arguments when he couldn’t attend in person, allowing him to ask questions remotely. He isn’t doing so this time,” wrote Slate reporter Mark Joseph Stern on X, formerly Twitter.