[scantis]

The word used was "aemuna" or "æmunatō". The most basic translation is reliability. The other word much later was pisteōs with loyalty in its most basic translation.

The concept of faith as you describe it is a late interpretation, morphing both concepts together. Jobs "faith" is his reliability of character, neither his believe nor faith, yet axiomatically the definition behind those words. That if you choose to believe in God and have faith your reliability of character will come or strive to have it.

Without being misleading, you may have it without any believe or faith in God.

[taylorlapeyre]

What is a "late interpretation" in your view? What time period exactly? Job has been read as a story that directly dialogues on the possibility of faith and trust in God in the face of evil for millennia. See The Babylonian Talmud (Bava Batra 15a-16b), Midrash Rabbah (Genesis Rabbah, Exodus Rabbah), Saadia Gaon's commentary on Job, even Maimonides. And on the Christian side, Take Origen, John Chrysostom, and especially Gregory The Great's Moralia in Job in the 500s CE.

[scantis]

With late interpretation I mean what is after the fact.

Job has not read his own story.

A late interpretation for me is viewing him, with what he has defined.

If faith would be praying five times a day and avoiding shellfish, his story becomes meaningless.

As you pointed out well, there are many scholars who discussed faith and belief over time. I am not a religious authority, think of me as a simpleton. You may choose their take on the word, it is a late interpretation to me. It could be a whole book on the matter.

The direct translation is reliable.