כְּק֣וֹל מַרְכָּב֗וֹת עַל־רָאשֵׁ֤י הֶֽהָרִים֙ יְרַקֵּד֔וּן כְּקוֹל֙ לַ֣הַב אֵ֔שׁ אֹכְלָ֖ה קָ֑שׁ כְּעַ֣ם עָצ֔וּם עֱר֖וּךְ מִלְחָמָֽה׃
他們在山頂上跳躍，響聲如同戰車的轟隆聲，又如火焰吞燒碎稭的聲音；他們如同一群強盛的民，擺陣準備作戰。
Abarbanel
1. And it mentions the sounds of the men that the sounds are loud and powerful and they scare the people. They are like the "voice of chariots on the mountaintops" that the same voice that is heard from a distance because of the chariots and because of the mountains. And the Ibin Ezra writes that the chariots don't travel on high places but these are able to go on the mountaintops. And also like the sound of a flame. That flame is the one that consumes the straw and creates a loud sound when it burns the sticks, like the "cracklings of nettles under a kettle" (Koheles 7:6). that was the sound of the Babylonians. Meaning that they weren't a people that was shy and timid and not tested by war, but rather were powerful and were trained for war from youth.
Rashi
arrayed for battle Heb. עֱרוּךְ. Since it is in the construct state, it is vowelized with a “hataf segol.”