The Lord was not transfigured just this one time: certain transfigurations preceded and followed this one.

He was first transfigured when he came into the world from the bosom of the Father (Jn 1:18). ‘Although he was in the form of God, he emptied himself and took the form of a slave’ (Ph 2:6-7).

The eternal became temporal; the immense became small; the Creator, a creature; God, man; the maker, what was made.

This transfiguration is as great as the distance between God and man; it is immense and infinite.

We should note very carefully that the Lord is not said to be transfigured in such a way that he laid aside or emptied out his previous divine form, or in some way changed it, when he accepted the form of a slave.

Rather, he is called ‘transfigured’ because he did not appear to us in the form of God but in the human form that he assumed for our sake.

His second transfiguration occurred when ‘he was found human in appearance’ (Ph 2:7).

He not only came in human likeness by truth of nature and by participation in punishment, though not in guilt, but he was also found human in appearance; that is, he appeared like other people.

He lived as if he were weak and sinful, eating and drinking with sinners so that he was called a drunkard (Mt 11:19).

This is called the transfiguration of association; by it he had compassion on the weak, and adapted himself to them, so that he could draw them to himself and impress his form upon them.

This second transfiguration is much less drastic than the first. The first was from the mountain of eternity into the vale of tears; the second occurs within that vale of misery.

Achard of St Victor (c.1100- 1172): Sermon on the Transfiguration, from Works, tr. Hugh Feiss, OSB Cistercian Studies 165, (Cist. Publ., Kalamazoo, MI, 2001) pp. 191-200.