'Rinse your mouth/gargle with (rose/blossom water or Zamzam water or in case of culture differences Pierian spring water), before you dare speak of/about..'.
This is an Arabic saying. This is used right off after one has said something insulting, degrading or improper about someone or something. It means that your speak trash and their is no right to what one says, and that they are not in the small class, sophistication or esteem as that person or thing to speak about or them in such a degrading manner. It is a quick retort.
What is an equivalent to this?