He was speaking about the Spirit, whom those who believed in Him were later to receive. For the Spirit had not yet been given, because Jesus had not yet been glorified.

Proverbs 1:23
If you had repented at my rebuke, then surely I would have poured out my spirit on you; I would have made my words known to you.

Joel 2:28
And afterward, 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.

John 1:33
I myself did not know Him, but the One who sent me to baptize with water told me, 'The man on whom you see the Spirit descend and rest is He who will baptize with the Holy Spirit.'

John 8:54
Jesus answered, "If I glorify Myself, My glory means nothing. The One who glorifies Me is My Father, of whom you say 'He is our God.'

John 12:16
At first His disciples did not understand these things, but after Jesus was glorified they remembered what had been done to Him, and they realized that these very things had also been written about Him.

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

John 13:31
When Judas had gone out, Jesus said, "Now the Son of Man is glorified, and God is glorified in Him.

John 14:16
And I will ask the Father, and He will give you another Advocate to be with you forever--

John 16:14
He will glorify Me by taking from what is Mine and disclosing it to you.

John 17:1
When Jesus had spoken these things, He lifted up His eyes to heaven and said, "Father, the hour has come. Glorify Your Son, that Your Son may glorify You.

John 20:22
When He had said this, He breathed on them and said, "Receive the Holy Spirit.

Acts 1:4
And while they were gathered together, He commanded them: "Do not leave Jerusalem, but wait for the gift the Father promised, which you have heard Me discuss.

Acts 2:4
And they were all filled with the Holy Spirit and began to speak in other tongues as the Spirit enabled them.

Acts 2:33
Exalted, then, to the right hand of God, He has received from the Father the promised Holy Spirit and has poured out what you now see and hear.

Acts 19:2
and asked them, "Did you receive the Holy Spirit when you became believers?" "No," they answered, "we have not even heard that there is a Holy Spirit."

(But this spoke he of the Spirit, which they that believe on him should receive: for the Holy Ghost was not yet given; because that Jesus was not yet glorified.)