It's possible that you're thinking of:
* "What is, is." This is a philosophical statement that highlights the reality of the present moment and the inevitability of certain things. It is attributed to various philosophers and has no single definitive source.
* "What must be, must be." This phrase also focuses on accepting the inevitable and highlights the powerlessness of individuals in the face of fate. It's a more common saying, but still not attributed to a specific individual.
If you could provide more context or the situation where you heard this phrase, it might be possible to pinpoint the actual quote or the speaker.