In general, when an item (or one of its parts) is made to be used for a miṣva, a Tefilin for example, it must be done with the specific intention of being used for the fulfillment of that miṣva. The leather-straps used for making a Tefilin, for instance, can not be coming from left overs of leather used for manufacturing shoes or other items. The leather to be used to make a Tefilin has to be produced specifically for the purpose of fulfilling the miṣva of Tefilin. Before processing the leather, the artisan says explicitly: leshem miṣvat tefilin, [I'm processing this leather to be used...] for the purpose of the miṣva of Tefilin.
Similarly, in the case of the maṣa ( in English "Matzah") the maṣotthat will be consumed during the first two nights of Pesah (maṣot miṣva) must be elaborated with the purpose of the miṣva of eatingmaṣa. According to some rabbis this purposefulness is part of what gives a maṣa its status of shemura (Rabbi E. Melamed).
Normally, the maṣot are made by the Jewish workers with this intention in mind. But what about the maṣot that are made mainly by a machine? Do we consider that the "human intentionality" extends, so to speak, from the worker that activates the machinery to the machinery itself, or is this process discontinued as soon as a non-human factor intervenes? Although many rabbis agree that this is the case, to avoid this debate some rabbinic authorities recommend to use for the two nights of Pesah--when eating maṣais mandatory-- a maṣa that was elaborated by hand.
Therefore, if one can find and afford it, one should get hand mademaṣot for the first two nights of Pesah. If not, one can use for the first two nights maṣa shemura made by machine.
