In Paul's day 'Arabia' meant the kingdom of the NABATAEANS — the Arab traders whose capital was the rock-cut city of Petra, controlling the incense routes south and east of Judea (their king Aretas IV is named at 2 Corinthians 11:32, whose governor tried to seize Paul at Damascus). After his Damascus-road call Paul 'went away into Arabia' (Galatians 1:17) rather than up to Jerusalem — the point of the itinerary being what it AVOIDS, the human apostles. ⚠ What he DID there he never says: the guesses run from a quiet retreat of prayer and reflection to immediate preaching (which would fit the Nabataean hostility that later put a bounty on him). The silence is argument, not evasion.