Midrash for Pesachim 71:19

רבי עקיבא אומר מצה ומרור מה מרור שאינו בכורים אף מצה שאינה בכורים אי מה מרור שאין במינו בכורים אף מצה שאין במינה בכורים

are kneaded with lukewarm water, and he [the official in charge] guards them that they should not become in connection with the eating of unleavened bread on the night of Passover. leaven? - If this was said of [very] careful men [priests], shall it [also] be said of those who are not careful?<span class="x" onmousemove="('comment',' This is the answer. The preparing of unleavened bread for meal-offerings was in the hands of priests, who were very careful and could be relied upon not to permit it to ferment. But unleavened bread for Passover is made in every home, and the people could not be trusted to take so much care.');">¹⁹</span> If so, let it also be permitt to wash [the grain];<span class="x" onmousemove="('comment',' I.e., to soak it slightly in water and then pound it so as to remove the bran and make a fine flour.');">²⁰</span> why did R'Zera say in the name of Rabbah B'Jeremiah in Samuel's name: The wheat for meal-offerings must not be washed? - The kneading was done by careful men, but the washing would not be done by careful men.<span class="x" onmousemove="('comment',' This was not the priest's duty.');">²¹</span> Yet must the kneading be done by careful men [priests]; surely it is written, and he shall bring it to Aaron's sons the priests: and he shall take thereof his handful.'<span class="x" onmousemove="('comment',' Lev. II, 2.');">²²</span> from the taking of the handful and onwards is the duty of the priesthood; this teaches concerning the pouring [of oil] and the mixing,<span class="x" onmousemove="('comment',' Which preceded the taking of the handful; v. ibid. 1, 2.');">²³</span> that it is valid [when done] by any man? - The kneading, granted that it is not [done] by careful men, yet it is [done] in the place of careful men.<span class="x" onmousemove="('comment',' I.e., in the Temple Court, which is frequented by priests, and these would take heed that whoever kneaded it should not permit fermentation.');">²⁴</span> For a Master said: The mixing is valid [if done] by a lay Israelite; [but if done] without the wall[s] of the Temple Court, it is invalid. Thus this excludes washing, which is not [done] by careful men nor in the place of careful men. And wherein do they [all other meal-offerings] differ from the meal-offering of the 'omer,<span class="x" onmousemove="('comment',' V. Glos.');">²⁵</span> for it was taught: The meal-offering of the 'omer is washed and heaped up?<span class="x" onmousemove="('comment',' For the water to drain off.');">²⁶</span> - A public [offering] is different.<span class="x" onmousemove="('comment',' This was a public offering, and everything in connection with it, right from the harvesting of the grain, was done under competent guidance and vigilance.');">²⁷</span> Our Rabbis taught: You might think that a man discharges his duty with first fruits,<span class="x" onmousemove="('comment',' E.g., a priest to whom an Israelite brought the first fruits of his wheat harvest.');">²⁸</span> therefore it is stated, in all your habitations shall ye eat unleavened bread,<span class="x" onmousemove="('comment',' Ex. XII, 20.');">²⁹</span> teaching, [it must be] unleavened bread which is eaten in all your habitations, thus excluding first fruits, which may not be eaten in all your habitations save in Jerusalem [alone]: this is the view of R'Jose the Galilean. R'Akiba said: Unleavened bread and bitter herbs [are assimilated]:<span class="x" onmousemove="('comment',' Num. IX, 11: they shall eat it with unleavened bread and bitter herbs.');">³⁰</span> just as bitter herbs which are not first fruits [are required],<span class="x" onmousemove="('comment',' For only the seven species enumerated in Deut. VIII, 8, ('a land of wheat and barley, and vines and fig trees and pomegranates; a land of oil olive and honey') are subject to the law of first fruits.');">³¹</span> so unleavened bread which is not first fruits [must be eaten]. If so, just as bitter herbs of a species not subject to first fruits [are required], so unleavened bread species [of grain] not subject to first fruits [is meant],

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