za.lal describes mountains shaking or trembling in the context of a divine descent.

The two occurrences depict mountains shaken or trembling in connection with a descent from heaven: Isaiah 63:19 presents the expected reaction, while Isaiah 64:2 places it within imagery of fire and the nations' trembling.

1. Mountains shaken at a divine descent · dominant

   Both occurrences use the same Niphal perfect, third common plural form in imagery of a descent from heaven. In Isaiah 63:19 the APB renders the clause "the mountains would have quaked before you," while Isaiah 64:2 continues the same scene with fire imagery and says that "the nations tremble before you."

   Isaiah 63:19Isaiah 64:2

In the Anselm Project Bible: In Isaiah 63:19 the APB presents the mountain response as "the mountains would have quaked before you." Isaiah 64:2 continues the surrounding scene with fire and trembling nations; Its precise rendering of the repeated form there is not isolated.