For the phrase “that which had not been told them they shall see, and that which they had not heard they shall contemplate,” see Romans 15:21.

Note that this quote in the New Testament is not taken from the Hebrew Bible but from the Greek Septuagint (LXX) which translates into English as “those who were not informed about
him shall see and those who did not hear shall understand” (Translation by NETS — for the Greek version see the title’s tooltip)