A dove, representing the Holy Spirit, hovers low in the sky directly above the lamb, surrounded by concentric semicircles of white and yellow hues of varying luminosity, the outermost of which appear like nimbus clouds. Thin golden beams emanating from the dove resemble those surrounding the head of the lamb, as well as those of the three figures in the Deësis in the upper register. The rays seem to have been painted by van Eyck over the finished landscape, and serve to illuminate the scene in a celestial, supernatural light. This is especially true with the light falling on the saints positioned directly in front of the altar. The light does not give reflection or throw shadow, and has traditionally been read by art historians as representing the New Jerusalem of Revelation which in 21:23, had "no need of the sun, neither of the moon, to shine in it; for the glory of God did Lighten it".