天子穆穆 tiān zǐ mùmù

tiān zǐ mùmù phrase the son of Heaven looks solemn
Domain: Literary Chinese 文言文
Notes: Quote: from 是可忍也，孰不可忍 in Book 3 八佾 Ba Yi of the 論語 “Analects of Confucius” (Amies 2021 tr.; see also Legge 1861, vol. 1, Confucian Analects, p. 19)