so gibi aziz ol

thanks / teşekkürler

Su gibi aziz ol. : (i wish you) be valuable like water. usually people use this as good wishes when you give/fetch them a glass of water 

aziz: valuable, precious

So you would say to a person like this

Me : Zahmet olmazsa su getirebeilir misin bana?

Them : Olur

Me : Tsklr su gibi aziz olsun!

I think only old people use that expression. It sounds out-dated. Just say thanks.

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