The Shulhan Aruch (Siman 554) records the Halacha that one cannot fulfil the Misva of Masa with stolen Masa. One must properly own the Masa for the Misva. Therefore, the Poskim write that one should pay for his Masa before Pesach to insure that he has a made bona fide Kinyan D’oraita-act of acquisition recognized by the Torah.
The question is whether one may pay for the Masa with a check. If the check clears before the holiday, there is certainly no problem; that is the same as cash. However, if he pays right before the holiday, it is better to add some cash to the payment, since the check does not have the status of Halachic money. Even though it is not the full amount, it is still considered a Kinyan D’oraita. If the seller does not want to receive payment before the holiday, taking the Masa home is considered a Kinyan Haser (courtyard) which is also D’oraita.
Hacham Bension rules that if someone is a guest for the Seder, he does not have to perform a specific Kinyan to acquire the Masa of his host. It is assumed that when the host allows him to partake of his Masa that he is granting him full possession. It is preferable for the host to declare to himself before the Seder that the Masa he is dispensing to his guests is a gift and this constitutes Da’at Makneh-intent to give.
