I'll agree that the lyrics are hard to make out in many places. Here's what I found on a Website called genius.com. I'll add my corrections in italics, but there's still a lot I can't understand.
CALVARY HILL (Shirley Collins)
[Verse 1] Joseph, husband, come tell me why Our lovely son was left for to die Too young was he, for his to blood to spill Down yon green slopes of Calvary Hill
[Verse 2] That(?) little foot when the stable was bare All wrapped in cree(?) from the cold night air This heart of mine with grief would fill To see his body hang on Calvary Hill
[Verse 3] Hard is the iron that holds him there Sharp are the thorns in (on?) his dark hair; But harder yet, and darker still Are the hands that nailed him on Calvary Hill
[Verse 4] May god forgive them that did the deed: The judge, the spy and the men of greed To save a fortune(?) my boy was killed By Roman soldiers on Calvary Hill
[Verse 5] Come Joseph, husband, and let us go To some lone corner and clean our wound(?) The cross may shake but the boy is still His life is ended on Calvary Hill
The melody is "Lady Franklin's Lament" or "Bob Dylan's Dream." Is there a more official name for the melody?