כָּל־גֶּיא֙ יִנָּשֵׂ֔א וְכָל־הַ֥ר וְגִבְעָ֖ה יִשְׁפָּ֑לוּ וְהָיָ֤ה הֶֽעָקֹב֙ לְמִישׁ֔וֹר וְהָרְכָסִ֖ים לְבִקְעָֽה׃
Every valley shall be lifted up, and every mountain and hill shall be made low; and the rugged shall be made level, and the rough places a plain;
Read halakhic rulings (Jewish law) on Isaiah 40:4: and classical halakhic sources.