the meaning of "cup"

[chance22]

I saw expressions like "Her cup overran with gratitude"; "My cup of happiness is full". I wonder what's the exact meaning of cup here. Are these idioms with reference to certain story？Would you help me? Thank you.

 

[SoothingDave]

It's from the Bible.

https://en.wikipedia.org/wiki/My_Cup_Runneth_Over

 

[Charlie Bernstein]

It's from a Bible phrase : My cup runneth over. You can look it up.

 

[Yankee]

I saw expressions like "Her cup overran with gratitude"; "My cup of happiness is full". I wonder what's the exact meaning of cup here. Are these idioms with reference to certain story？Would you help me? Thank you.

It is a metaphor that expresses feeling or emotion.