Urizen is given credit for creation of the world,
but at least part of it actually goes to Los.
Look at Chapter IV of the Book of Urizen where in seven ages "in a state of dismal woe" Los proceeded to endow Urizen with the five senses.
Properly speaking Blake meant by sons of Los
just about everyone and everything:
"Thou seest the gorgeous clothed Flies that dance &; sport in summer
Upon the sunny brooks & meadows: every one the dance
Knows in its intricate mazes of delight artful to weave:
Each one to sound his instruments of music in the dance,
To touch each other & recede; to cross & change & return.
These are the Children of Los; thou seest the Trees on mountains
The wind blows heavy, loud they thunder thro' the darksom sky
Uttering prophecies & speaking instructive words to the sons Of men:
These are the Sons of Los! These the Visions of Eternity
But we see only as it were the hem of their garments (cf Matthew 9:20-22)
When with our vegetable eyes we view these wond'rous Visions."
(Milton, plate 26; Erdman, page 123)
Some Sons of Los
Reiger even claims the Holy Word a garment which may be called a Son of Los.