8 What said He further? “The world cannot hate you.” What is this, but, The world cannot hate its lovers, the false witnesses? For you call the things that are evil, good; and the things that are good, evil. “But me it hates, because I bear witness concerning it, that its works are evil. Go ye up to this feast.” What means “to this”? Where ye seek human glory. What means “to this”? Where ye wish to prolong carnal joys, not to meditate on eternal joys. “I go not up to this feast, because my time is not yet full come.”
On this feast-day you seek human glory; but my time, that is, the time of my glory, is not yet come. That will be my feast-day, not running before and passing over these days, but remaining for ever; that will be festivity, joy without end, eternity without a blot, serenity without a cloud. “When He had said these words unto them, He abode still in Galilee. But when His brethren had gone up, then went He also up unto the feast, not openly, but as it were in secret.” Therefore “not to this feast-day,” because His desire was not for temporal glory, but to teach something to profit, to correct men, to admonish them of an eternal feast-day, to turn away their love from this world, and to turn it to God.
But what means this, “He went up as it were in secret to the feast”? This action of the Lord also is not without meaning. It appears to me that, even from this circumstance that He went up as it were in secret, He had intended to signify something; for the things that follow will show that He thus went up on the middle of the feast, that is, when those days were half over, to teach even openly. But he said, “As it were in secret,” meaning, not to show Himself to men. It is not without meaning that Christ went up “as it were in secret” to that feast, because He Himself lay hid in that feast-day. What I have said as yet is also under cover of secrecy. Let it be manifested then, let the veil be lifted, and let that which was secret appear.
Source: Tractates on the Gospel of John (New Advent)