The phrase comes from Antoine Daniel's French YouTube series What The Cut, where he commented on strange and viral internet videos in an energetic, sarcastic style. Ferme ta gueule is a blunt French expression meaning shut up, and in this context it works as an exaggerated, comic interruption rather than a literal insult. Clips from the series have long circulated as reaction sounds among French-speaking creators, and the line survives because it is instantly recognisable, easy to drop into edits, and needs little context to land.