Literature Reference: When the body is idle, there is nothing to do; when the mind is idle, there is nothing to think. Source from 'Qiu Chi Er Shou Yi' by Bai Juyi.
思: Thought, intellect. In names, it often signifies quick thinking, sharp wit, and intelligence.
心: Heart and intention, often used in names to signify sincerity, is conducive to attracting noble assistance.
Meaning: Si Xin signifies inner peace, desirelessness, and a tranquil state of mind, pursuing spiritual freedom and transcendence.