In Deuteronomy 16:2 it says one has to slaughter the passover sacrifice from the flock AND herd. Then in verse 3 it says: “You shall not eat anything leavened with it; for seven days you shall eat matzot with it.”
What’s the it, and does this mean one should eat that as well for seven days during chag hamatzot.
The explanation of [Rei 16:2] is brought to include both the korbon Pesach (flock) and the korbon Chagigah (herd). We know that the Korbon Pesach must only from the flocks (sheep and goats). Thus, herds must refer to a different korbon. As translated
You shall slaughter the Passover sacrifice to the Lord, your God, [of the] flock, and [the Festival sacrifices of the] cattle, in the place which the Lord will choose to establish His Name therein.
As Rav Hirsch explains:
For in the mishna (Pesachim 69,b) it is taught that if the Pesach offering by itself is not sufficient for a meal for the whole company on whos behalf it is brought, a חגיגה offering is also to be brought on the fourteenth of Nisan which has to be eaten first so that the Pesach offering is eaten when on is no longer hungry.
Instead of translating the beginning of verse 3 as
You shall not eat leaven with it;
Rav Hirsch translates it as
Thou shalt no eat any leaven in connction with it;
This means Rav Hirsch says that the איסור of Chametz starts with the Korbon Pesach just as the mitzvah of matzah and continues for the entire seven days of Pesach.
Thus the halacha is laid down that the positive command to eat mazzo is dependent on the negative command of chometz in material, in person, and in time.
