Helpful articles on Christ in the Old Testament, the pre-Incarnation theophanies of our Lord, by Archimandrite Vasillios Papavassiliou.

Overview:

https://www.pravmir.com/article_1224.html

Series:

The God of the New Testament in the Old Testament (part 1)

The God of the New Testament in the Old Testament (part 2)

The God of the New Testament in the Old Testament (part 3)

The God of the New Testament in the Old Testament (part 4)

The God of the New Testament in the Old Testament (part 5)