Andrei Rublev's great icon of the Holy Trinity is not unique in taken the story of Abraham and Sarah entertaining the three men at the Oak of Mamre and addressing them in the singular as "My Lord", it was an Easter Christian image of the Trinity. What is significant is the brilliance of his theological interpretation, an icon is a theological statement before it is a picture.
From right to left, the Father, Son and Holy Spirit. Behind the Son is the Oak of Mamre, it reminds us of the cross, "at the heart of the Trinity", the brown and blue of the Son's clothing is a statemt of his Divine and Human natures, as does his two fingers held over the dish in which is a lamb, signifying His sacrifice and Eucharist.
The Father is dressed in ineffable Light, the Son and Spirit direct their gaze towards him, and he towards them. The house behind the Father reminds us that the Father is met through his house the Church
The Spirit is clothed in both the garment of Divinity and Fecundity, green is the Orthodox colour of the Holy Spirit.
The table is bopth a sign of the altar and the universe, the hand of the Holy Spirit rests on both.
The whole composition is based on circles and triangles, oneness and trinity.
There is something significant about the niche in the table, but I have forgotten what it is, anyone know?
What I find truly significant in Rublev's interpretation is the place of the viewer in the composition, he imvites us into the picture, to participate in the inner life of the Trinity. This is the great insight into the nature of God that Christianity offers, God is distant in his unicity but is imannent in his Trinity, not merely the God of knowledge but through the Son he is the God of human experience (even to the point of being clothed in the humus of the grave) and the Spirit being the lifegiver, in both the natural sense, but also in the Supernatural sense.