It was used for scratching itches on the back where the hand could not reach, and was thus amenable [ju] to the wishes [i] of the user. "Hence the adoption of a refined name for this humble house-hold article.
或背脊有癢，手不能到，用以搔爬，如人之意。」於是實用的生活器具就有了這樣一個吉祥雅緻的名稱。