Anyway.. my apologies for the delay -- work was a bit of a mess, this morning and I both 1) forgot and 2) forgot.
Due to some things I really wish I could say to a lot of people I have to be around a little too much, lately, I found a list of 105 semi-snarky, generally-mostly-clean comebacks if someone's testing your calm. These have been censored, but not by me.
As always, you can ask for as many or as few as you want; specific numbers or at random.
Maybe your character says it; maybe it's said to them... maybe it takes you off on a different tangent entirely! Sky's the limit, as they say!!