Menachot 70 – Five Species of Grain

Rav Zeira asked a question, "Wheat kernels that came down with the rain, can one make the two loaves on Shavuot with it?" Does “from your dwelling places” exclude places outside the Land of Israel, or does it exclude even the tornado?

Rabbi Shimon ben Pazi asked, “An ear of grain that reached the third of its size before the Omer, then one uprooted it and replanted after the Omer, is it permitted old crop, because the root is more important, or is forbidden new crop, because of the new growth?”

For many laws the following species are special: wheat, barley, spelt, oats and rye. One who makes dough from them is obligated to give challah – the first portion of the dough – to a kohen. They combine with each other to form the amount (about 5 pounds) necessary for challah. It is forbidden to eat them before the Omer is brought, and it is forbidden to harvest them before Passover. The Omer permits them as long as they have taken root before it. These species that can leaven and become prohibited on Passover, and these same species are what matzah is made of.

Art: Camille Pissarro - Field of Oats in Eragny