Literature Reference: 除非物外者，谁就此经过。——《游长宁公主流杯池二十五首 十》 Unless one is detached from worldly affairs, who would pass by here? Source from 'Twenty-five Poems of You Changning Princess Liubei Pond, No. 10.'
物: Objects, items.
外: Exterior; the outside. It is the opposite of "inside" or "within."
Meaning: Detached from worldly affairs, seeking freedom and tranquility of the mind.