Literature Reference: 春日无人境，虚空不住天。—— 《陪李梓州王阆州苏遂州李果州四使君登惠义寺》 In the spring day, the uninhabited realm, the void cannot hold the sky. Source from 'Accompanying Li Zizhou, Wang Langzhou, Su Suzhou, and Li Guozhou to Mount Huiyi Temple.'