# A river of fire flowed out from before him

"Fire poured out in front of him like water in a river" 

# before him

The word "him" refers to God, the Ancient of Days from 

# millions

"thousands of thousands" or "great numbers of people"

# one hundred million

"tens of thousands times tens of thousands" or "uncountable numbers of people"

# The court was in session

"The judge was ready to judge" or "The judge was seated"

# the books were opened

"the books of evidence were opened"