Elihu speaks of people not being fully able to understand God's deeds as if people were only able to see those deeds from far away. AT: "they do not fully understand them" (See: [[rc://en/ta/man/translate/figs-metaphor]])
This refers to how long God has existed. AT: "people cannot know how long he has lived" or "people cannot know his age" (See: [[rc://en/ta/man/translate/figs-idiom]])