A clip of U.S. Sen. Sherrod Brown, D-Ohio, went viral on Monday, after the senator admonished one of his Republican colleagues for not wearing a mask in the chamber.

“I’d start by asking the presiding officer to please wear a mask as he speaks since people below him are —” Brown, when called on to speak, said to U.S. Sen. Dan Sullivan, R-Alaska, before being cut off.

Sullivan, who was at the dais as the Senate was debating Kristi Haskins Johnson’s nomination to a U.S. District Court seat, responded.

“I don’t wear a mask when I’m speaking, like most senators,” Sullivan retorted. “I don’t need your instruction.”

Brown criticized his Republican colleagues about their priorities in focusing on judge nominations over passing COVID-19 relief legislation.

“I know you don’t need my instruction, but there clearly isn’t much interest in this body in public health,” Brown said. “We have a president who hasn’t shown up at the Coronavirus Task Force meeting in months. We have a majority leader that calls us back here to vote on an unqualified nominee and at the same time to vote for judge after judge after judge, exposing all the people who can’t say anything.”

Brown said that Senate Majority Leader Mitch McConnell “just doesn’t care” about public health or that of staffers.

The video of the exchange, which Brown’s office posted online, circulated heavily on social media.

U.S. Sen. Ted Cruz, R-Texas, mocked Brown’s words as “idiotic” in a post on Twitter.

“@SherrodBrown is being a complete ass,” Cruz posted. “He wears a mask to speak — when nobody is remotely near him — as an ostentatious sign of fake virtue.”

However, many were quick to respond to Cruz, pointing out that, though Brown, who was masked, and Sullivan were spaced apart, the video showed Senate staffers only a few feet from Sullivan and that Brown had specifically cited concern for those working near him.

“It’s pretty revealing that you don’t consider the staffers right in front of Sullivan as people worth protecting,” historian Kevin Kruse said to Cruz in a responding post. “Only the senators matter, right?”

On Tuesday, U.S. Sen. Chuck Grassley, R-Iowa, 87, who serves on the Senate Judiciary Committee, announced that he had tested positive for COVID-19.

Grassley, the longest serving Republican and president pro tempore of the Senate, said he was isolating at home as a result.

“I’m disappointed I wasn’t able to vote today in the Senate, but the health of others is more important than any record,” Grassley said in a statement, noting that it was the first Senate vote he would miss in 27 years.

To date, more than 25 members of Congress have reported positive cases of COVID-19, with at least 150 staff in the Capitol infected.