Isaiah 40:4

4 Fill in the valleys, and level the mountains and hills. Straighten the curves, and smooth out the rough places.

Isaiah 40:4 Meaning and Commentary

Isaiah 40:4

Every valley shall be exalted, and every mountain and hill
shall be made low
Which is not to be understood literally, but, as Kimchi says, parabolically and mystically: the meaning is, that in consequence of John's ministry, and our Lord's coming, such who were depressed and bowed down with the guilt of sin, and were low and humble in their own eyes, should be raised up and comforted; and that such who were elated with themselves, and their own righteousness, should be humbled; their pride and haughtiness should be brought down, and they treated with neglect and contempt, while great notice was taken of lowly minded ones; see ( Luke 14:11 ) and ( Luke 18:14 ) : and the crooked shall be straight and the rough places plain;
what before was dark and intricate in prophecy should now become clear; and such doctrines as were not so well understood should now become plain and easy.

Isaiah 40:4 In-Context

2 “Speak tenderly to Jerusalem. Tell her that her sad days are gone and her sins are pardoned. Yes, the LORD has punished her twice over for all her sins.”

3 Listen! It’s the voice of someone shouting, “Clear the way through the wilderness for the LORD ! Make a straight highway through the wasteland for our God!

4 Fill in the valleys, and level the mountains and hills. Straighten the curves, and smooth out the rough places.

5 Then the glory of the LORD will be revealed, and all people will see it together. The LORD has spoken!”

6 A voice said, “Shout!” I asked, “What should I shout?” “Shout that people are like the grass. Their beauty fades as quickly as the flowers in a field.