My Birkat brings all the boys to the yard, I can teach and I won’t even charge. Or something like that. About a year ago, I was caught in what appeared at the time to be a mind-numbing debate over some minutiae regarding a single word in the Birkat Hamazon that appears in Karaite texts. It turns out the debate was not mind-numbing at all and a simple look through the Cairo Geniza would have solved the whole issue and explained a whole lot more.