The concept of `圣旨` is deeply rooted in the political and philosophical idea of the “Mandate of Heaven” (天命, Tiānmìng). The emperor was not just a ruler; he was the “Son of Heaven” (天子, Tiānzǐ), chosen by the heavens to govern. Therefore, his edict was seen as a reflection of celestial will. A `圣旨` was a physical object of immense power, typically a long scroll of high-quality silk or brocade, intricately woven and bearing the imperial seal. Decrees were often announced with the famous opening line, “奉天承运,皇帝诏曰” (fèng tiān chéng yùn, huángdì zhào yuē), meaning “Having received the Mandate of Heaven, the Emperor proclaims…” This ritual reinforced the edict's divine and unchallengeable nature.
In modern times, since China no longer has an emperor, `圣旨` is not used in any official capacity. Its usage is almost entirely historical or metaphorical.
This is the most common way you'll hear `圣旨` today. It's used as a hyperbole to describe an order from an authority figure in everyday life that feels absolute and must be obeyed without question. It's almost always used with a tone of light-hearted complaint or sarcasm.
In these cases, the term exaggerates the power of the person giving the order, humorously comparing them to an all-powerful emperor.