וַיִּֽחַר־אַ֤ף בָּלָק֙ אֶל־בִּלְעָ֔ם וַיִּסְפֹּ֖ק אֶת־כַּפָּ֑יו וַיֹּ֨אמֶר בָּלָ֜ק אֶל־בִּלְעָ֗ם לָקֹ֤ב אֹֽיְבַי֙ קְרָאתִ֔יךָ וְהִנֵּה֙ בֵּרַ֣כְתָּ בָרֵ֔ךְ זֶ֖ה שָׁלֹ֥שׁ פְּעָמִֽים׃
발락이 발람에게 노하여 손뼉을 치며 발람에게 말하되 내가 그대를 부른 것은 내 원수를 저주하라 함이어늘 그대가 이같이 세 번 그들을 축복하였도다
Sforno
ויספק את כפיו, as a sign that he had abandoned hope of achieving his objective, seeing that Bileam was cursing those whom he wanted to be the cursers.
Or HaChaim
ויתר אף בלק..ויספק את כפיו, "Balak became angry… and clapped his hands, etc." He expressed his anger by clapping his hands together.