כָּל־יֹשְׁבֵ֥י תֵבֵ֖ל וְשֹׁ֣כְנֵי אָ֑רֶץ כִּנְשֹׂא־נֵ֤ס הָרִים֙ תִּרְא֔וּ וְכִתְקֹ֥עַ שׁוֹפָ֖ר תִּשְׁמָֽעוּ׃ (ס)
All ye inhabitants of the world, and ye dwellers on the earth, When an ensign is lifted up on the mountains, see ye; And when the horn is blown, hear ye.
Read halakhic rulings (Jewish law) on Isaiah 18:3: and classical halakhic sources.