Few people are as familiar with the Bible as was Blake. He included Biblical references innumerable times throughout his work as a way of packing symbols together for the reader to unpack as he journeys through the dense imagery.
The extent of biblical knowledge which went into producing the following section of Milton is demonstrated by Harold Bloom in this introduction (page xii) to Bloom's Classic Critical Views: William Blake. Bloom's attention is focused on the confrontation between Urizen and Milton beside the brook Arnon.
Milton, Plate 19 , (E 112)
"Urizen emerged from his Rocky Form & from his Snows,
And he also darkend his brows: freezing dark rocks between
The footsteps. and infixing deep the feet in marble beds:
That Milton labourd with his journey, & his feet bled sore
Upon the clay now chang'd to marble; also Urizen rose,
And met him on the shores of Arnon; & by the streams of the
Silent they met, and silent strove among the streams, of Arnon
Even to Mahanaim, when with cold hand Urizen stoop'd down
And took up water from the river Jordan: pouring on
To Miltons brain the icy fluid from his broad cold palm.
But Milton took of the red clay of Succoth, moulding it with care
Between his palms: and filling up the furrows of many years
Beginning at the feet of Urizen, and on the bones
Creating new flesh on the Demon cold, and building him,
As with new clay a Human form in the Valley of Beth Peor."
Bloom who wrote the commentary for The Complete Poetry & Prose of William Blake edited by David V. Erdman makes this statement:
"This magnificent passage does assume the reader's knowledge of some crucial biblical references. The Arnon is a river flowing westward into the Dead Sea and dividing off the Trans-Jordan lands of the Israelites from Moab. Numbers 21:14 associates the Arnon and the Red Sea, by which the Israelites escaped the deadly bondage of Egypt. The Arnon in Blake has the same significance, as Milton Percival observes, for through it one passes from the body of death into the generative body, from Urizenic law to the sacrifice of Luvah for man. Mahanaim (Genesis 32:2) is where Jacob wrestled with God until he had secured a blessing and the name of Israel. Succoth is where Jacob went afterwards, to build a house and booths (Genesis 33:17), the booths giving the place its name, and associating the story with the harvest festival, where four plants represent four classes of men united as one man in worship. Beth Peor is the burial place of Moses in the land of Moab. Drawing all this together and applying it to Blake's passage, we suddenly behold the audacity and clarity with which Blake had molded his sources.
Urizen fears that Milton is coming to overthrow his laws, for Milton began by taking off the robe and ungriding himself from the oath of Urizen-Jehovah's covenant with Moses. So Urizen goes forth to battle, turning the warm clay Milton walks on to freezing and purgatorial marble. They meet and wrestle, two silent and mighty champions, on the shores of Arnon, the body of law striving with the human form divine. Their struggle is like the wrestling of Jehovah and Jacob, except that Milton will not repeat Jacob's mistake, he wants to reform God, and not just extract a blessing for himself.
As the battle continues, Urizen attempts an icy intellectual baptism of Milton with Jordan water, but Milton fights back by taking the Adamic red clay of Succothe, emblem of a human harvest from the same valley where the body of Moses or Urizenic law is forever buried. Milton's activity is artistic and gives the sculptor's gift of life, of red flesh to cold marble, making God into a Man, Urizen into Adam.
This extraordinary struggle attains an apotheosis in one on Blake's superb condensations on intellectual strife transmuted into saving metaphor."
IMAGE: Jerusalem, Plate 45
Milton, Plate 21 , (E 115)
"But Milton entering my Foot; I saw in the nether
Regions of the Imagination; also all men on Earth,
And all in Heaven, saw in the nether regions of the Imagination
In Ulro beneath Beulah, the vast breach of Miltons descent.
But I knew not that it was Milton, for man cannot know
What passes in his members till periods of Space & Time
Reveal the secrets of Eternity: for more extensive
Than any other earthly things, are Mans earthly lineaments.
And all this Vegetable World appeard on my left Foot,
As a bright sandal formd immortal of precious stones & gold:
I stooped down & bound it on to walk forward thro' Eternity."
Bloom : "I offer this as an epitome of Blake's unique greatness. Few passages in Western poetry equal this in originality and soul-arousing eloquence."