2. 攤開手掌是表現誠實的傳統方式

When someone swears to tell the truth in a court of law, they put one hand on a religious text and raise their other hand into the air, palm facing whoever they're speaking to.
人們在法庭上發誓講真話時，會把一只手放在宗教經文上，另一只手舉在空中，手掌面對說話對象。

That's because an open palm has been associated with "truth, honesty, allegiance, and submission" throughout Western history.
這是因為在整個西方歷史中，攤開的手掌一直與“真理、誠實、忠誠和順從”聯系在一起。