performative

Relating to or being an utterance that performs an act or creates a state of affairs by the fact of its being uttered under appropriate or conventional circumstances, as a justice of the peace uttering I now pronounce you husband and wife at a wedding ceremony, thus creating a legal union, or as one uttering I promise, thus performing the act of promising.

A performative utterance.

Being enacted as it is said.

A performative utterance.