en_tn_condensed/job/38/21.md

Undoubtedly ... so large

"It is obvious that you do not know, because you were not born when I created them, and you are not very old". Yahweh uses mocking irony to emphasize that Job does not understand light and darkness.

for you were born then

"for you were already born when I created them". The word "then" refers to the time when light was created and separated from darkness.

the number of your days is so large

"you have lived so many years"