Bachan means to test or examine, especially as a refiner tests precious metal. It is used for God testing the hearts of humans (Jeremiah 17:10; Psalm 17:3), for trials that reveal the quality of faith (Job 23:10), and also for humans challenging God (Malachi 3:10 — God invites Israel to test Him in tithes).
Divine testing in Scripture is never about God learning something He did not know — He is omniscient. Rather, bachan points to the process by which genuine faith is revealed, confirmed, and refined. Trials function like a furnace that burns away dross and purifies gold. The tested believer who endures emerges stronger (Job 23:10: 'When he has tested me, I will come forth as gold'). This connects directly to the New Testament teaching on trials producing perseverance (James 1:3).