en_tn/job/28/03.md

A man sets an end to darkness

Here "sets an end to darkness" represents shining a light in the darkness. People used a lantern or a torch for light. Alternate translation: "A man carries light into dark places" (See: rc://en/ta/man/jit/figs-metonymy)

to the farthest limit

"to the farthest parts of the mine"

obscurity ... thick darkness

These two phrases are used together to emphasize that the mine is extremely dark. (See: rc://en/ta/man/jit/figs-doublet)