Golden State Warriors coach Steve Kerr, among the NBA’s the loudest and most respected voices on sociocultural and political issues, responded to Kyrie Irving’s antisemitic Twitter post before his team’s game against the Orlando Magic on Thursday.

Framing Irving’s implicit support of an antisemitic movie through the perils of social media, Kerr warned against everyone—not just celebrities in the public sphere—posting potentially inappropriate and insensitive material without considering the ramifications of doing so.

“Words matter. Words really, really matter. And in modern society with social media, the way things can sort of fan across the globe exponentially and get a million hits immediately, every comment matters, everything you say matters,” Kerr said.

“We have to be more vigilant as a society. We can’t just be accepting comments that are so destructive and insulting to people. And it’s crucial to everybody, whether you’re a professional athlete or not, think before you put something out there that’s so damaging.”

Irving came under fire from all sides last week after tweeting a link to the 2018 film Hebrews to Negroes: Wake Up Black America. The movie, directed by Ronald Dalton Jr., is based on a book of the same name and rife with antisemitic tropes, including that a secret cabal of Jewish people control global society and that the Holocaust was a hoax.

The Brooklyn Nets superstar refused to apologize in his first public remarks since sparking the controversy, getting into a heated argument with ESPN reporter Nick Friedell during which he espoused belief in the “New World Order” conspiracy theory.

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Irving released a joint statement with the Nets and Anti-Defamation league on Wednesday, stressing that he is “aware of the negative impact of my post towards the Jewish community” and does not believe everything in the documentary “was true or reflects my morals and principles.” Irving and the Nets will also be donating $500,000 to causes and organizations that “work to eradicate hate.”

He once again refused to apologize for his post or subsequent comments less than 24 hours later.

When pressed on Thursday to answer affirmatively or negatively whether he harbors any antisemitic beliefs, Irving repeatedly said, “I cannot be antisemitic if I know where I come from,” an ostensible reference to the view held by extreme factions of the Black Hebrew Isrealites asserting that people of color are the “true” children of Israel—a central thesis of Hebrews to Negroes: Wake Up Black America.

Kerr has been increasingly outspoken on cultural and politics matters since Donald Trump’s rise as the standard bearer of right-wing American politics. The Warriors coach has butted heads with the disgraced former president through the media on several separate occasions, also expressing strong support for the Black Lives Matter movement and stronger gun control measures.

In May, after a gunman killed 19 children and two teachers at Robb Elementary School in Uvalde, TX, a visibly angry Kerr spent his pregame media availability before the Warriors’ playoff game against the Dallas Mavericks imploring lawmakers to “do something!” Kerr’s father, Malcolm, was murdered by members of a Shia Lebanese militia in 1982 while serving as president of the American University of Beirut.