Adam Clarke on John 12:38

That the saying of Esaias - Or, Thus the word of Isaiah was fulfilled. So I think ἱνα (commonly rendered that) should be translated. For it certainly does not mean the end the Pharisees had in view by not believing; nor the end which the prophet had in view in predicting the incredulity of the Jews; but simply, such a thing was spoken by the prophet, concerning the Jews of his own time, and it had its literal fulfillment in those of our Lord's time.

Our report - The testimony of the prophets, concerning the person, office, sufferings, death, and sacrifice of the Messiah. See Isa 53:1, etc.

The arm of the Lord - The power, strength, and miracles of Christ.