John 12:39

For this reason they could not believe, ¹  because again Isaiah said,

For this reason they could not believe, because, as Isaiah says elsewhere:

For this reason they could not believe, for Isaiah said again,

But the people couldn’t believe, for as Isaiah also said,

First they wouldn't believe, then they couldn't--again, just as Isaiah said:

For this reason they were unable to have belief, because Isaiah said again,

And so they could not believe, because Isaiah also said,

Therefore they could not believe, because Isaiah said again:

For this reason they could not believe, ¹  because again Isaiah said,

¹ sn The author explicitly states here that Jesus’ Jewish opponents could not believe, and quotes Isa 6:10 to show that God had in fact blinded their eyes and hardened their heart. This OT passage was used elsewhere in the NT to explain Jewish unbelief: Paul’s final words in Acts (28:26-27) are a quotation of this same passage, which he uses to explain why the Jewish people have not accepted the gospel he has preached. A similar passage (Isa 29:10) is quoted in a similar context in Rom 11:8.