en_tn/psa/091/005.md

terror in the night

The psalmist speaks of "terror" as if it were a spirit or fierce animal that could attack at night and so terrify people. Alternate translation: "things attacking you at night" (See: rc://en/ta/man/jit/figs-metonymy)

in the night ... by day

These two phrases taken together refer to all possible times of night and day. (See: rc://en/ta/man/jit/figs-merism)

the arrow that flies by day

"Arrow" here is a metonym for the people who shoot the arrows. Alternate translation: "people attacking you with arrows during the day" (See: rc://en/ta/man/jit/figs-metonymy)