11:1 And the LORD said unto Moses, Yet will I bring one plague [more] upon Pharaoh, and upon Egypt; afterwards he will let you go hence: when he shall let [you] go, he shall surely thrust you out hence altogether.
11:2 Speak now in the ears of the people, and let every man borrow of his neighbour, and every woman of her neighbour, jewels of silver, and jewels of gold.
11:3 And the LORD gave the people favour in the sight of the Egyptians. Moreover the man Moses [was] very great in the land of Egypt, in the sight of Pharaoh's servants, and in the sight of the people.
Verses 1-3 summarize instructions, which Moses had previously received and implemented (in ch.12), in preparation for the Passover and for Israel's subsequent departure from Egypt.
These instructions were given to Moses, prior to the Plague of Darkness (Ex 10:21-23). Note the evidence of this timing:
v.4-8 conclude Moses' last audience with Pharaoh (which started in Ex 10:24-29).
Because the time of judgment was to be 'midnight' (cp. v.4 with 12:29) of the day of Moses' final confrontation with Pharaoh, the Passover lamb would have been chosen on the day before the Plague of Darkness. (The lamb was to be selected and kept for four days, prior to being slain and eaten. cp. 10:22,23; 12:3,6)
Therefore, the differentiation between Egypt and Israel, by which Israel had light in their dwellings, was the symbolic presence of the Lamb. (Re: The Lamb as light, see Isa 60:1,2; Mat 4:13-16; Joh 1:4,5; Joh 8:12)
Aaron did not appear before Pharaoh with Moses at the time of the ninth plague, as he had at all previous plagues (10:24-29 - 11:4-8).
On this night, Aaron, himself a 'firstborn,' could not leave his house. cp. v.5; 12:12,13
11:4 And Moses said {to Pharaoh}, Thus saith the LORD, About midnight will I go out into the midst of Egypt:
11:5 And all the firstborn in the land of Egypt shall die, from the firstborn of Pharaoh that sitteth upon his throne, even unto the firstborn of the maidservant that [is] behind the mill; and all the firstborn of beasts.
11:6 And there shall be a great cry throughout all the land of Egypt, such as there was none like it, nor shall be like it any more.
11:7 But against any of the children of Israel shall not a dog move his tongue, against man or beast: that ye may know how that the LORD doth put a difference between the Egyptians and Israel.
11:8 And all these thy servants shall come down unto me, and bow down themselves unto me, saying, Get thee out, and all the people that follow thee: and after that I will go out. And he went out from Pharaoh in a great anger.
The LORD warned Pharaoh, through Moses, of the final plague:
Plague #10 - the Death of the First-born -
False gods judged - Men who honored themselves above the LORD God.
The Pharaohs were worshipped as gods.
The magician's response - Since this plague would affect every segment of society (v.5),
the magicians also would suffer the effects of death and mourning.
Pharaoh's response - his heart had become thoroughly hardened (v.9,10)...
he would lose his first-born son (heir to the throne). (12:29,30)
he and his servants would compel Israel to depart from them (cp. v.1,8; 12:31-33).
11:9 And the LORD said unto Moses, Pharaoh shall not hearken unto you; that my wonders may be multiplied in the land of Egypt.
11:10 And Moses and Aaron did all these wonders before Pharaoh: and the LORD hardened {HB=chazaq, strengthened} Pharaoh's heart, so that he would not let the children of Israel go out of his land.
'Moses and Aaron' were involved in 'all these wonders' (ie., the nine plagues).
But God's answer, in the final plague, would be the work of the LORD alone: "... I will go out..." (v.4,5).