In the sketches for his self-portrait, Hsu brushed some calligraphy to read, "The roots of the tree constantly extend down, through the sand and rocks, ever downward. Yet their groping is all for naught because there is nothing to absorb."
在自畫像的草圖上，許雨仁用毛筆草草寫著「樹根在土裡不停往下生，在沙、在石頭裡，不停地往下生，卻是沒有用的放射和吸收… …」。