For He Himself, just like His Begetter is unalterable and immutable, and was never capable of any passibility (susceptibility to pain). But when He became flesh, that is became man, He appropriated the poverty of humanity to Himself; firstly, because even though He became man, He still remained God; and secondly, because He accepted the form of a servant even though He is free in His own Nature.

 And even though He Himself is the Lord of glory, He is said to receive glory.  And even though He Himself is Life, He is shown to be brought back to life. And even though He Himself is King of all, He receives dominion over all. Even though He is equal to God the Father, He obediently endured His sufferings and the Cross. Because all these things were part and parcel of the human condition He adopted them as being implied along with the flesh,  and so He fulfilled the economy, though always remaining what He was.1

    It is fitting to understand the union of Emmanuel to be such as the soul of a man might be thought to have with its own body. For the soul appropriates the the things of the body even though in its proper nature it is apart from the body’s natural passions, as those which impinge on it from without. For the body is moved to physical desires, and the soul which is within it feels these things too, because of the union, but in no way does it participate in these things, except in so far as it takes the fulfilment of desire as its own gratification. If the body was struck by a sword, or tortured on an iron grid, then the soul would share in its grief, because it is its own body which is suffering. But in its own nature the soul does not suffer anything of these things. 
    This indeed is how we attribute the union to Emmanuel. For it was necessary that the soul united to it should share in the grief of its own body, so that rising above these sufferings it could submit itself as obedient to God. But it is foolish to say that God the Word shared in feeling the sufferings. For the Godhead is impassible and is not in our condition. Yet [the Word] was united to the flesh endowed with a rational soul, and when the flesh suffered, even though He was impassible, He was aware of what was happening within it, and thus as God, even though He did away with the weakness of the flesh, still He appropriated those weaknesses of his own body. This is how He is said to have hungered, and to have been tired, and to have suffered for our sake.
    Accordingly, the union of the Word with humanity can reasonably be compared with our condition. Just as the body is of a different nature to the soul, still from both we say that one man results, so too from the perfect hypostasis of God the Word and from a humanity perfect in its own right there is one Christ, and the selfsame is at once God and man. As I said earlier, the Word appropriated the affairs of his own flesh because it is his body, no one else's. And He communicates, as to his own flesh, the operation of his own divine powers. This was how He was able to give life to the dead, and to heal the sick.

    And so, even though He said through the holy prophets; “I gave My back to the scourge, My cheeks to their blows. I did not turn away My face from the shame of their spitting”  (Is.50.6); and again: “They have pierced My hands and My feet, they have numbered all My bones” (Ps.21.17-18); and again: “They gave Me hyssop for food, and in My thirst they offered Me vinegar” (Ps.68.22); even so we attribute all these things to the Only Begotten himself. For He suffered them economically in the flesh for our sake and in accordance with the scriptures: “For by his wounds we have been healed, and He himself was wounded because of our sins” (Is.53.5). We recognise, however, that He was impassible by nature, yet if, as I have just said, the same one was at once God and man, then the sufferings certainly belonged to his humanity, while it was the proper characteristic of God to be understood to be impassible. 
    If we think like this, we will preserve piety, and shall come, by means of these orthodox thoughts and opinions, to arrive at “the prize of our heavenly calling” (Phil.3.14) in Christ: through Whom and with Whom, to God the Father be glory, with the Holy Spirit, through the ages of ages. Amen.3

1. Saint Cyril of Alexandria: Scholia on the Incarnation, in:  John McGuckin: Saint Cyril of Alexandria and the Christological Controversy p. 298. Available from:  an excellent deal at $22.95 & eligible for FREE Super Saver Shipping,   ***** reviews.

2. Ibid, p 300,301.

3. Ibid, p 335.
There is an older translation of St. Cyril's work on the Incarnation available online

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