Yiddish: a gezunt dir in pupik

[been4years]

Hi, mentors,
Thank you for reading my thread!

I came across this sentence in a book that I am translating and I really tried to find what this sentence would mean, but I couldn't.
In the book, it implied that this is from Yiddish, but I don't think this is Yiddish.(May be German?)
The full sentence is,
"Oyoyoy, 'my children,' he says! What do you know about children! A gezunt dir in pupil... 'children'!

What would this mean? What language would this be?

Thank you in advance!

 

[sound shift]

Yes, it's Yiddish, and it literally means "Good health to your belly button". (Your "pupil" is a typo; it should be "pupik".)
Jewish Words And Phrases

 

[Mori.cze]

As for what language: the word pupik (belly button) is a loanword from Czech (or maybe some other Slavonic language)

 

[been4years]

Sound shift and Mori.cze,

Yes, it's pupik. It just was auto-corrected and I didn't notice.
Thank you very much!