Don't that take the rag off the bush!

An exclamation of disbelief, as at some surprising, shocking, or amazing occurrence. Well, don't that take the rag off the bush! I wasn't expecting to have you here for Christmas! We just bought our first house, and now my husband's been laid off. Now don't that take the rag off the bush? The dog figured out how to open the latch on the fence, and the cows took off after him! Don't that take the rag off the bush!