the angel who bears the secret is connected with the meridian of the sun, for the text says that he appeared as ‘the sun was crossing the midpoint of its course.’ The angel bears the mysterious elixir on his head and, by his relationship to the meridian, makes it clear that he is a kind of solar genius or messenger of the sun who brings ‘illumination,’ that is, an enhancement and expansion of consciousness.
Jung identifies the Meridian of the Sun in the Isis vision as the locus of a solar messenger whose appearance at solar culmination symbolises an intensification and broadening of consciousness.
, Alchemical Studies, 1967thesis