The Spirit had not been inactive or missing up to this point in scripture. He was at the beginning, active in the creation of all things (Gen 1:2); He came upon prophets in the Old Testament (1 Sam 10:10), even upon God’s enemies (Num 24:2); and He “filled” people ( Ex 35:31, Luke 1:67). What is spoken of here is the fulfillment of (Joel 2:28) which would happen on the Day of Pentecost. The Holy Spirit had briefly empowered people, but the glorification of Christ was going to enable Him to come and live within us permanently, making us brand new people and causing rivers of living water to flow from within us.

Gen 1:2  Now the earth was formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the waters.

Isa 10:10  When they arrived at Gibeah, a procession of prophets met him; the Spirit of God came upon him in power, and he joined in their prophesying.

Num 24:2  When Balaam looked out and saw Israel encamped tribe by tribe, the Spirit of God came upon him

Ex 35:31  and he has filled him with the Spirit of God, with skill, ability and knowledge in all kinds of crafts—

Luke 1:67  His father Zechariah was filled with the Holy Spirit and prophesied:

Joel 2:28  “And afterwards, I will pour out my Spirit on all people. Your sons and daughters will prophesy, your old men will dream dreams, your young men will see visions.

glorified = speaking of the death of Jesus on the cross without which the Holy Spirit could not have been given as it was (and is). (12:16; 12:23; 13:31)

John 12:16  At first his disciples did not understand all this. Only after Jesus was glorified did they realise that these things had been written about him and that they had done these things to him.

John 12:23  Jesus replied, “The hour has come for the Son of Man to be glorified.

John 13:31  When he was gone, Jesus said, “Now is the Son of Man glorified and God is glorified in him.