Albert Barnes Commentary Matthew 26:67

"Then did they spit in his face and buffet him: and some smote him with the palms of their hands," — Matthew 26:67 (ASV)

They spit in his face. This, among the Jews, as among us, signified the highest contempt and insult (Numbers 12:14; Isaiah 1:6; Job 30:10).

And buffeted him. That is, they struck him with their hands closed, or with the fist.

Others smote him with the palms of their hands. The word used in the original here means, literally, to strike with rods. It also means to strike the mouth with the open hand, as if to prevent a person's speaking, or to express abhorrence of what he had spoken.