Bitter Withy –

if that soupçon of anti-Jewish sentiment was inserted by Peter Bellamy, I'd say his instincts were sound. Now the rich young lords are not just snotty young snobs but snotty young racist snobs to boot. Drown 'em all!

Interestingly, I've always heard it as "a Jewess' son" and always sung it that way. Makes even more sense theologically.