In my previous article on depicting the Trinity, which was initially intended as a stand-alone post, I reached the conclusion that Andrei Rublev’s masterful iconographic rendering of “the hospitality of Abraham” pictorial tradition was the height of Trinitarian visual depictions, in its mystical and symbolic highlighting of the divine attributes of the Triune Godhead. I argued in favor of this iconography as opposed to other various images of the Trinity which represented the Father as an old man.
To summarize my argument: because the Father has never been seen by man (Jn 6:46; Jn 14:8-9) it’s both inappropriate to depict the Father and pedagogically misleading and confusing to do so. And though the “Ancient of Days” imagery from the prophet Daniel’s vision is there used to represent an aspect of the Father, that title is also used by many Church fathers to describe the Son as well, and so is not unique to the Father nor an actual description of his likeness. The Son may be depicted in his humanity because we have seen him; the Spirit may be depicted in the likenesses in which he uniquely manifested himself (as a dove or tongues of fire); but the Father (having only been described in terms also used of Jesus in Revelation 1:14) who Jesus said explicitly that no man has seen, ought not to be depicted qua Father.
I think this argument could be strengthened by the fact that depicting the Father as an old man à la the Ancient of Days imagery still means having to depict his face, which “no man can see and live” (Ex 33:20). When we depict Jesus’ face (even if the tradition of his visual features through the ages may be questioned), it’s certainly because his face has been seen by many. Depicting the clothes and hair and throne of the Father as “Ancient of Days” is one thing; but depicting the very essence of the unseen Father who has no human face just seems wrong. This was also the widespread consensus of the early Church both East and West.
But I wanted to follow up that last article to ask the question: how, then, did the early Church represent the Trinity in iconographic form? I don’t think that Rublev in the 15th century was the first to interpret the three angels who visited Abraham as a mystical representation of the Holy Trinity (though he certainly made it the most explicit by “zooming in” on the angelic figures and leaving out the other traditional elements of the scene like Abraham, Sarah, the preparing of the meal, etc). But there are other instances in the Scriptures where the three persons of the Trinity are all explicitly working together: the Baptism of Jesus, for example. And there are times when it would be helpful to visually communicate the presence and agency of the Father. How did the Church manage this without drawing him as an old man?
The answer was often with the “Hand of God” motif, or the Manus Dei. Because God is so frequently described in the Scriptures as accomplishing things “by his right hand and his mighty arm,” the image of a hand extending from heaven became a common way to represent the agency of God (specifically often of the Father). Yes, this is still an anthropomorphizing of the Father who doesn’t have literal hands, but it’s merely figurative and (crucially) doesn’t involve making up a face for him. It also doesn’t run the pedagogical risk of confusing the Father with a disembodied hand, any more than we run confusing the Spirit with an actual bird or a floating tongue on fire.
When used in the icon of the Baptism of Christ, we see the Son of God incarnate, the Spirit of God descending as described “like a dove,” and the figurative Hand of God representing the blessing given by the Father through the thunderous voice that was heard. This is clearly depicting the entire Trinity in a seemly way without being misleading or confusing.
Outside of the highly mystical “depiction” of the Father in Rublev’s rendering of the Hospitality of Abraham icon, I think the safest, most traditional, and most reasonable way to depict the Father is via the Manus Dei from heaven.