Literature Reference: 天寒犹讲律，雨暗尚寻经。—— 《题冲沼上人院》 Even in the cold, the law is still taught; in the dark rain, the scriptures are still sought. Source from 'Ti Chong Zhao Shang Ren Yuan'.
雨: The life-giving rain that nourishes all things.
暗: Darkness, dimness, and secret signals.
Meaning: Dark rain symbolizes the perseverance in seeking truth and wisdom even in adversity.