For the source text click/tap here: Pesachim 40
To download, click/tap here: PDF
Ex 12:!5
וּשְׁמַרְתֶּם, אֶת-הַמַּצּוֹת
These 3 words triggers the prooftext for sh'mura matza and our attempt to follow the mesorah leading to the interesting phenomena of reform Jews participating in this chumra!