Jamieson, Fausset and Brown on John 12:16

16. when Jesus was glorified, then remembered they that these things were written of him, &c.--The Spirit, descending on them from the glorified Saviour at Pentecost, opened their eyes suddenly to the true sense of the Old Testament, brought vividly to their recollection this and other Messianic predictions, and to their unspeakable astonishment showed them that they, and all the actors in these scenes, had been unconsciously fulfilling those predictions.