Pesahim 38a and Pesahim 38b, ma’aser sheni as financially belonging to Gd according to R. Meir, and therefore not obligated in hallah, not usable as matzah for the Seder, nor for an etrog on Sukkot. Then, whether hallah can be used Seder night, since it can never be taken out of Jerusalem, and matzot assumed to be for sacrifices and why they cannot be used.
