Midras Keluaran 3:9: Shemot Rabbah, Midrash Tanchuma Buber, Midrash Tehillim & Sifrei Devarim

“I have come down to deliver them from the hand of Egypt and to take them up from that land to a good and expansive land, to a land flowing with milk and honey, to the place of the Canaanites and the Hittites and the Emorites and the Perizzites and the Hivvites and the Yevusites” (Exodus 3:8).
“I have come down to deliver them from the hand of Egypt…” – the Holy One blessed be He said to Moses: ‘I told their patriarch Jacob: “I will go down with you into Egypt and I will take you up…” (Genesis 46:4). Now I have come down here to take his descendants up, as I said to Jacob their patriarch. To where will I take them up? To the place from which I took them, to the land about which I took an oath to their ancestors.’ That is what is written: “And to take them up from that land…”
“And now, behold, the outcry of the children of Israel has come to Me and I have also seen the oppression that the Egyptians are oppressing them” (Exodus 3:9).
“And now, behold, the outcry of the children of Israel has come to Me,” – until now, their outcry has not come to Me, as the end that I said to Abraham had not yet arrived: “And [they] will serve them, and they will afflict them four hundred years” (Genesis 15:13).
“Go now, and I will send you to Pharaoh, and take My people the children of Israel out of Egypt” (Exodus 3:10).
“Go [lekha] now, and I will send you to Pharaoh” – Rabbi Elazar said: Lekha [ending with the letter heh] is emphatic, saying that if you do not deliver them there is no one else to deliver them.¹¹The midrash is reading lekha, go, as a conjunction of lekh ata, go you.

(Exod. 3:9:) BUT NOW LOOK, THE CRY OF ISRAEL'S CHILDREN HAS COME UNTO ME, AND I HAVE ALSO SEEN THE OPPRESSION < WITH WHICH THE EGYPTIANS OPPRESS THEM >. <This verse > teaches that the Holy One looked at the Egyptians, at how they had enslaved Israel. It is so stated (ibid.): LOOK, THE CRY OF ISRAEL'S CHILDREN HAS COME UNTO ME, AND I HAVE ALSO SEEN THE OPPRESSION…. I, as it were, am with them. <As for THE OPPRESSION > WITH WHICH THE EGYPTIANS OPPRESS THEM, (according to vs. 8) I HAVE COME DOWN TO DELIVER THEM <OUT OF THE HAND OF THE EGYPTIANS >.

“Behold, I am sending an angel” (Exodus 23:20) – the Holy One blessed be He said to Moses: The one who protected the patriarchs will protect the descendants. Likewise, you find with Abraham, when he blessed his son Isaac, he said to him: “The Lord, God of the heavens…He will send His angel before you” (Genesis 24:7). Jacob our patriarch, what did he say to his children? “The angel who redeems me [from all evil]” (Genesis 48:16). He said to them: ‘He redeemed me from Esau, he redeemed me from Laban, he fed me and supported me during the years of famine.’ The Holy One blessed be He said to Moses: ‘Now, too, the one who protected the patriarchs will protect the descendants, as it is stated: “Behold, I am [sending an angel].”’
Every place that an angel is seen, the Divine Presence is seen, as it is stated: “An angel of the Lord appeared to him in a flame of fire” (Exodus 3:2), and immediately, “God called to him” (Exodus 3:4). Moreover, when Israel cries out before Him, salvation will come to them. So it was at the bush, as it is stated: “Now, behold, the outcry of the children of Israel has come to Me” (Exodus 3:9). Likewise with Gideon, “An angel [of the Lord] came.… The angel of the Lord appeared to him…” (Judges 6:11–12).¹⁷Following this, in verse 13, Gideon complains to the angel about Israel’s oppression at the hands of Midian. The midrash will now cite the angel’s response to Gideon. “He said: Go with this strength of yours and save Israel” (Judges 6:14). Likewise, in the future, when he will reveal himself, redemption will come to Israel, as it is stated: “Behold, I am sending My messenger, and he will clear a way before Me” (Malachi 3:1).