oracle; revelation; divine message
Refers to a message from a deity or spirit, often delivered through a medium or shrine. The honorific prefix ご adds a respectful tone.
I received a divine message at the shrine.
tedious talk; pretentious speech; saucy talk
Used sarcastically or critically for long-winded, self-important, or impertinent speech. Often implies the speaker is going on and on as if delivering a divine pronouncement.
I'm fed up with his tedious lectures.
There he goes again with his pretentious talk.
お告げ is a more common and neutral term for a divine message or premonition, while ご託宣 can sound more formal or sarcastic.
Standard kanji spelling with honorific prefix ご.
Alternate spelling using the kanji 御 for the honorific prefix.
Combination of the honorific prefix ご and 託宣 (oracle, divine message). The sarcastic sense likely developed from the idea of someone speaking as if delivering a divine pronouncement.