11:9. And he went out from Pharao exceeding angry. But the Lord said to Moses: Pharao will not hear you, that many signs may be done in the land of Egypt.
11:10. And Moses and Aaron did all the wonders that are written, before Pharao. And the Lord hardened Pharao's heart, neither did he let the children of Israel go out of his land.
The Lord hardened, etc… See the annotations above, chap. 4.21, and chap. 7.3.
Exodus Chapter 12
The manner of preparing, and eating the paschal lamb: the firstborn of
Egypt are all slain: the Israelites depart.
12:1. And the Lord said to Moses and Aaron in the land of Egypt:
12:2. This month shall be to you the beginning of months; it shall be the first in the months of the year.
12:3. Speak ye to the whole assembly of the children of Israel, and say to them: On the tenth day of this month let every man take a lamb by their families and houses.
12:4. But if the number be less than may suffice to eat the lamb, he shall take unto him his neighbour that joineth to his house, according to the number of souls which may be enough to eat the lamb.
12:5. And it shall be a lamb without blemish, a male, of one year; according to which rite also you shall take a kid.