From Commentary on Isaiah (ca. 415)
Those who were children of night and of darkness have become children of light. On them the day has spread its light, the Sun of Righteousness has risen and the bright morning star has appeared….
The Lord has generously stretched out his hand to them and crowned them with many bountiful gifts, as the Prophet Isaiah affirms: “Everyone who sees them shall acknowledge them, because they are an offspring blessed by God” (61:9) to which he adds: “They will greatly rejoice in the Lord” (61:10). For he gives them joy at once.
It is appropriate that these words personify the Church, for out of great joy she cries out: “Let my soul be glad in the Lord, for he has clothed me with the garment of salvation, and the robe of joy” (61:10).
Our Lord Jesus Christ is called the “robe of joy.” That is why the most-wise Paul writes to those who believe in Christ, “Put on the Lord Jesus Christ, and make no provision for the flesh, to gratify its desires” (Romans 13:14). Besides possessing salvation, those who wear Christ as a robe will enjoy happiness and their days will be filled with joy. The Savior himself says, “The thief comes only to steal and kill and destroy. I came that they may have life and have it abundantly” (John 10:10).
For Christ not only saves, he also gladdens his flowers with immeasurable joy. The word “abundance” here refers to life as it is known by the saints. Christ then is the garment from heaven above, the robe of immortality.
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 Isaiah 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.