This is one of the bluntest cautionary lines a querent can draw, and its subject is almost always a specific piece of speech. Something favourable is anticipated, an association with an influential person, an opportunity that looks settled, a result that seems certain, and the querent has been talking about it. The reading says that the talking is the problem and that misfortune follows from it directly, not from the underlying situation, which may well be sound.
The line's distance from the hexagram's single source of energy is what a reading should attend to. Whatever the querent is excited about originates with someone else, and the excitement has been borrowed rather than produced. Announcing it converts a real connection into a claim, and a claim of this kind is easy to test and difficult to survive. Practically the advice is silence until the thing exists: no forwarding of the news, no early credit taken, nothing said that would have to be walked back.
Unlike most lines in this hexagram, no correction is offered here, and that omission is worth reading honestly rather than softening. The text is describing a fault that is complete once committed, because words already spoken cannot be recalled. A querent who has not yet spoken is being given the one useful instruction available. A querent who has already spoken is being told to expect the consequence and to make no further claims on top of it.