Berean Study Bible
For this reason they were unable to believe. For again, Isaiah says:

King James Bible
Therefore they could not believe, because that Esaias said again,

American Standard Version
For this cause they could not believe, for that Isaiah said again,

Darby Bible Translation
On this account they could not believe, because Esaias said again,

Douay-Rheims Bible
Therefore they could not believe, because Isaias said again:

English Revised Version
For this cause they could not believe, for that Isaiah said again,

Young's Literal Translation
Because of this they were not able to believe, that again Isaiah said,