so that what was spoken by Isaiah the prophet would be fulfilled:

This fulfilled what was spoken by Isaiah the prophet:

In this way what was spoken by Isaiah the prophet was fulfilled: “He took our weaknesses and carried our diseases.”

For he is the one about whom Isaiah the prophet had spoken: “The voice of one shouting in the wilderness, ‘Prepare the way for the Lord, make his paths straight.’”

And concerning them the prophecy of Isaiah is fulfilled that says: ‘You will listen carefully yet will never understand, you will look closely yet will never comprehend.