John Lightfoot on Matthew 26:65

[Then the high priest rent his clothes.] "When witnesses speak out the blasphemy which they heard, then all, hearing the blasphemy, are bound to rend their clothes." "They that judge a blasphemer, first ask the witnesses, and bid him speak out plainly what he hath heard; and when he speaks it, the judges standing on their feet rend their garments, and do not sew them up again," &c. See there the Babylonian Gemara discoursing at large why they stand upon their feet, why they rend their garments, and why they may not be sewed up again [Sanhedr. cap. 7. hal. 10].