Because at Passover, when we have to eat unleavened bread, the rabbis say, what is the difference between dough that is made into bread, and dough that is made into unleavened bread, or "matzah"?
Deoarece, de Paste, cand trebuie sa mancam paine nedospita, rabinii intreaba care este diferenta dintre aluatul din care se face paine, si aluatul din care se face paine nedospita: matzah.