Dear Jim,

> The Buddha was occasionally referred to as the "Kinsman of the Sun".
> Does anyone know how this phrase originated? It may just be a standard
> honorific, but apparently the planet mercury is referred to as "Budh"
> in Indian astrology, so there may be a play on words here.

I can't remember the exact details, but it is connected with the Buddha's
clan (gotra) name which claims descent from Aaditya, the royal solar
lineage -- I think there is a corresponding, but inferior, lunar lineage. I
doubt that there is any connecton with Mercury.

Best wishes,
Stephen Hodge