Is there a witty turn of phrase that indicates one's performing an act that, in its doing, undermines, contravenes, or obviates itself?
This question relates to a similar idea, but I have it in my mind that there is a saying that describes this state of affairs. "Cutting off one's nose to spite one's face" is not quite what I'm going for because the act of cutting off the nose doesn't negate itself. I'm thinking more of a line speaking about someone who breaks the speed limit on his way to defend himself in traffic court, or wiping off a table with a dirty sponge.
Best Answer
“Don’t sell your mule to buy a plow” seems to fit your description pretty well?
Although, that’s actually not one I knew until just now. I had a vague memory of a similar British one — “selling your X to pay for its Y”, or something — and googling to try to work out what it was, I found the above version, which seems to be from the southern US. I still can’t work out what the original one I was thinking of was — does the form ring a bell with anyone?