To "watch over" means to protect someone. Here "the blameless" refers to the blameless people. AT: "protects the blameless people" (See: [[rc://en/ta/man/translate/figs-idiom]] and [[rc://en/ta/man/translate/figs-nominaladj]])
# day by day
This is an idiom that means "continually." AT: "every day" (See: [[rc://en/ta/man/translate/figs-idiom]])