228. Separating Challah from Pesach Matzah

35:3 When matzah is baked for Pesach, even though each dough does not contain enough flour to require that challah be taken, when the matzos are all gathered together in their box, they are considered a unit and the unit contains enough to require challah. All the matzos should be placed inside the box; if one of them is partially in and patially out, it is still considered part of the unit. If one matzah is resting on top and not in the box at all, it is not part of the unit; covering the stack of matzos with a napkin would not change this. However, if one puts the matzos in a cloth and covers them with a cloth, then the cloth is considered their container and everything inside the cloth is a unit even though the middle portion may be uncovered. One should take care that no whole matzah is outside the covering. 35:4 Leaven taken from one mound of dough so that it may be used to cause another dough to rise must be taken before separating challah. However, leaven that is taken in order to ferment drinks must be taken after challah has been separated.