Rat's ass?
You are a specialists on rat's ass? It is indeed an unique opportunity to know that you are an expert who is a specialist in the observation of rodents' posterior. A rare specialisation to say the least.
Of course you don't care about a rodent's rectum (rat's ass as you mention) about about biblical, or any religious characters for that matter, but pray what does this indicate but your indignation of mentioning a Biblical character
Now, now, my good fellow, you do take the cake in living an existence in denial and obfuscation, if I have the liberty to say so.
Your sure do care and take cognisance of a rodent's rectum, what ho?
Really?
It reminds me of the words of William Shenstone, an English poet (18 November 1714 – 11 February 1763). His quote was:
A liar begins with making falsehood appear like truth, and ends with making truth itself appear like falsehood.
Personally, I am loathed to use such rather extreme words, but the drift is what I would endorse.
Pip pip, old bird.