This is personification, referring to the thunder as the voice of God. AT: "voice, which was as loud as thunder" or "very loud voice" (See: [[rc://en/ta/man/translate/figs-personification]])
This is an exaggeration to emphasize that the lightning lit up everything the writer could see. AT: "lightning lit up everything as far as you could see" (See: [[rc://en/ta/man/translate/figs-hyperbole]])
These two phrases have similar meanings and are combined for emphasis. (See: [[rc://en/ta/man/translate/figs-doublet]])
# your footprints
Asaph is speaking of Yahweh as if Yahweh was a person with feet. While this is personification, it should be translated literally, if possible. (See: [[rc://en/ta/man/translate/figs-personification]])
# your footprints were not seen
This can be stated in active form. AT: "no one saw your footprints" (See: [[rc://en/ta/man/translate/figs-activepassive]])
# You led your people like a flock
This simile compares God's people to a flock of animals. (See: [[rc://en/ta/man/translate/figs-simile]])
# by the hand of
The phrase "by the hand of" here means "by the action of" or "through the action of."