[1] The traditional good wishes before and on a Yom Tov is Chag Sameach. But Pesach we wish each other, Chag Kosher V'Sameach. Why do we add the word Kosher in the Pesach wishes? Throughout the year there are certain foods which we are permitted to eat (Kosher foods) and those which we are prohibited to consume (non-Kosher). Food which is Kosher is always Kosher and those which aren’t Kosher are not to be eaten anytime. As a result, it is easy to be careful with the observance of Kashrus. But Pesach is different than other Yomim Tovim since foods which are Kosher all year, like bread and cake, are prohibited on Pesach. In fact, the prohibition of eating Chametz on Pesach is much stricter than the prohibition of eating pork! In addition to eating, possession of Chametz is prohibited on Pesach. Because these items are Kosher all year long, yet prohibited during Pesach, we need to be extra careful and make a special effort to make sure we don’t come in contact with it during Pesach. Therefore, we add to the regular wish of “Chag Sameach” the word “Kosher”—wishing each other that the holidays should pass in a most Kosher way.