After Jesus' answer at his hearing, the high priest tears his garments and declares that Jesus has spoken blasphemy. Tearing clothing was an established physical expression of intense grief or horror.
In this setting the gesture also publicly announces the high priest's judgment about what he has heard.
Scripture repeatedly depicts people tearing garments in response to death, disaster, shocking news, or perceived offense against God. Clothing could therefore become a visible medium for expressing emotional and religious outrage.
The Gospel scene joins the gesture to the charge of blasphemy. The exact legal characterization of Jesus' words has been extensively debated, but within the narrative the high priest treats the statement as sufficient to end the search for further testimony.
Recognizing the gesture's cultural force helps the reader see the sudden turn in the hearing. The high priest does not merely state disagreement; he performs horror before the assembly.
The action marks the moment when Jesus' claims about his identity and future vindication become the central issue leading to the judgment pronounced against him.