בּ֣וֹא בַצּ֔וּר וְהִטָּמֵ֖ן בֶּֽעָפָ֑ר מִפְּנֵי֙ פַּ֣חַד יְהוָ֔ה וּמֵהֲדַ֖ר גְּאֹנֽוֹ׃
Gehe in den Felsen und verbirg dich im Staube vor dem Schrecken des Herrn, vor der Herrlichkeit seiner Hoheit.
Rashi on Isaiah
Come into the rock To come into the rock to escape in the cracks of the rocks.
Ibn Ezra on Isaiah
בא Infinitive: ‘ to enter ’ (comp. Hab. 2:3); or imperative : enter ; the advice which they will give each other.