He smote his hands together; a sign of great anger, Ezekiel 21:17, Ezekiel 22:13.
Related Commentaries of Numbers 24:10
Numbers 24:10
10 And Balak's anger was kindled against Balaam, and he smote his hands together: and Balak said unto Balaam, I called thee to curse mine enemies, and, behold, thou hast altogether blessed them these three times.