The phrase "you must have the patience of a Saint" is an idiomatic expression conveying a high level of patience or tolerance, often in the face of difficult or trying circumstances. When someone uses this phrase, they are essentially acknowledging or admiring someone's extraordinary capacity for remaining calm, composed, and patient, even in challenging or frustrating situations.
So, when someone says "you must have the patience of a Saint," they are essentially commending the individual's exceptional capacity for tolerance and calmness.
This expression is often used to acknowledge and appreciate someone's remarkable composure in the face of adversity or challenging circumstances.