William Burkitt on John 7:39

These words are the Evangelist St. John's commentary upon the foregoing promise; he tells us, that Christ spoke this of the miraculous gifts of the Spirit, which did accompany the descent of the Holy Ghost at the feast of Pentecost. For the Holy Ghost was not yet given:

Learn hence, That although the Spirit was in some measure given by God from the beginning to good men, yet the more plentiful effusion of it was deferred, till the ascension and glorification of Jesus Christ.