This is an ancient Celtic poem. No author is cited.  It sounds like the, "son," of God(Odin) lamenting whom in Celtic fair should be the character known as Esus. He is depicted in stone as being a carpenter surrounded by animals. The spear of Longinus from, "Odin," represents the lineage of Kings and their judgement. Odin means, "Father," and God as all earthly Kings descended in spirit from God into their human forms.