Literature Reference: 至怀无外，四海为家。—— 《礼记·礼运》 With utmost sincerity, the whole world becomes one's home. Source from 'The Book of Rites'.
至: Arrive; reach the pinnacle, the utmost, attaining the zenith.
怀: Yearning and reminiscence, here signify family harmony and mutual care.
Meaning: A heart of utmost sincerity embraces all things, holding the world within.