Is the "voice" in the wilderness, or is "the way of the Lord"?

There is no punctuation in the Hebrew...and learned people disagree:

A voice crying out in the wilderness,

"prepare the way of the Lord, 

make straight in the desert a highway for our God." 

Isaiah 40:3

...or...

A voice crying out, 

"in the wilderness prepare the way of the Lord, 

make straight in the desert a highway for our God."

Isaiah 40:3