en_tn_lite_do_not_use/ecc/11/08.md

happy in all of them

Here the word "them" refers to the years that a person is alive.

the coming days of darkness

Future time is spoken of as if the "days are coming" And, here the word "darkness" refers to death. AT: "how many days that he will be dead" (See: rc://en/ta/man/translate/figs-metaphor and rc://en/ta/man/translate/figs-euphemism)

for they will be many

Here the word "they" refers to the "days of darkness" AT: "for he will be dead for many more days than he is alive" or "for he will be dead forever"

Everything to come is vanishing vapor

Here "vanishing vapor" is a metaphor. Possible meanings are 1) AT: "No one knows what will happen after he dies" or 2) AT: "Everything to come is meaningless" (See: rc://en/ta/man/translate/figs-metaphor)

Everything to come

Possible meanings are 1) "Everything that happens after death" or 2) "Everything that happens in the future"