From Commentary on John 5.2 (ca. 425)
In a plan of surpassing beauty the Creator of the universe decreed the renewal of all things in Christ. In his design for restoring human nature to its original condition, he gave a promise that he would pour out on it the Holy Spirit along with his other gifts, for otherwise our nature could not enter once more into the peaceful and secure possession of those gifts.
He therefore appointed a time for the Holy Spirit to come upon us: this was the time of Christ’s coming. He gave this promise when he said: “In those days,” that is, in the days of the Savior, “I will pour out a share of my Spirit on all flesh.”
When the time came for this great act of unforced generosity, which revealed in our midst the only-begotten Son, clothed with flesh on this earth, born of woman, in accordance with Holy Scripture, God the Father gave the Spirit once again. Christ, as the firstfruits of our restored nature, was the first to receive the Spirit. John the Baptist bore witness to this when he said: “I saw the Spirit coming down from heaven, and it rested on him.” …
The only-begotten Son receives the Spirit, but not for his own advantage, for the Spirit is his, and it is given in him and through him… He receives it to renew our nature in its entirety and to make it whole again, for in becoming human he took our entire nature to himself. If we reason correctly, and use also the testimony of Scripture, we can see that Christ did not receive the Spirit for himself, but rather for us in him; for it is also through Christ that all gifts come down to us.
St. Cyril of Alexandria (376-444) was Patriarch of Alexandria and an influential theologian, who convened the Ecumenical Council of Ephesus in 431, which resolved the Nestorian Controversy by asserting the unity of Christ’s person, and defending the use of the Marian title “Theotokos,” the God-bearer. His commentary on St. John’s Gospel was a product of the early days of his episcopate. He is commemorated on various days on the liturgical calendar of Eastern and Western churches.