Literature Reference: 四望穷沙界，孤标出赡州。—— 《重修香山寺毕题二十二韵以纪之》 Gazing out over the boundless sandy expanse, a lone peak rises above Shanzhou. Source from 'Reconstructing the Xiangshan Temple and Composing Twenty-Two Rhymes to Commemorate It'.
沙: Sand, grains of sand.
界: Boundary. Limit.
Meaning: The sandy expanse represents the vastness of the desert or the mortal world, symbolizing boundlessness and transcendence.