The use of "spears" suggest war and combat. If the angels are to be seen as warriors, "they seem to represent his [Urizen's] own legions, who have lost the battle against the creator of the tiger and in the course of attempting to negate active energy have actually helped to create what they most feared--the wrath of righteousness . . . To Urizen the act of the stars in throwing down their spears would suggest the creation of the material world--the end of the 'wars of Eden' leading to the fall . . . The action of the stars here represents a fall in the war in heaven during which the 'demonic' orders, represented by the tiger, were created" (Adams 66).
Stars also throw down their spears in Night V of The Four Zoas.
"I well remember, for I heard the mild & holy voice
"Saying, 'O light, spring up & shine,' & I sprang up from the deep.
"He gave to me a silver scepter, & crown'd me with a golden crown,
"& said, 'Go forth & guide my Son who wanders on the ocean.'
"I went not forth: I hid myself in black clouds of my wrath;
"I call'd the stars around my feet in the night of councils dark;
"The stars threw down their spears & fled naked away.
"We fell. I seiz'd thee, dark Urthona."
[K310-11]
(qtd. in Adams 66-67).