When you have entered the land the LORD your God is giving you as an inheritance and have taken possession of it and settled in it, take some of the firstfruits of all that you produce from the soil of the land the LORD your God is giving you and put them in a basket. Then go to the place the LORD your God will choose as a dwelling for his Name and say to the priest in office at the time, "I declare today to the LORD your God that I have come to the land the LORD swore to our forefathers to give us." The priest shall take the basket from your hands and set it down in front of the altar of the LORD your God. Then you shall declare before the LORD your God: "My father was a wandering Aramean, and he went down into Egypt with a few people and lived there and became a great nation, powerful and numerous. But the Egyptians mistreated us and made us suffer, putting us to hard labor. Then we cried out to the LORD, the God of our fathers, and the LORD heard our voice and saw our misery, toil and oppression. So the LORD brought us out of Egypt with a mighty hand and an outstretched arm, with great terror and with miraculous signs and wonders. He brought us to this place and gave us this land, a land flowing with milk and honey; and now I bring the firstfruits of the soil that you, O LORD, have given me.""My father was a wandering Aramean..." Or, "My father was a lost Aramean..." Or, "My father was a perishing Aramean...." When we have come into the land that the Lord had given us, we are to say to the Lord, "My father, our father, was lost, wandering, dying in the desert. He was a stranger, homeless, without shelter. Until you gave him and me a home. Until you saved us. Until you gave us a place to live, land to grow food, water, livestock. Until you pulled us from our despair and fear and loneliness and gave us a place to worship you. We were aliens. You made us citizens. You made us at home."
Whatever the Hebrew people were or however they started, their identity was forged in Egypt. It was from Egypt they were rescued and it was during that deliverance that God set them apart and called them His own. During their flight, the Law was given, their relationship to God was defined through the covenant and God revealed more of Himself than He ever had in the past. The Hebrew people are a delivered people. They are a rescued people. They were homeless and oppressed until God stepped in.
That by itself, both humbling and revelatory, does not tell us very much about God. The simple fact that He rescued a specific nation or ethnic group, gave them some land and established a relationship with them does not inherently tell us who God is. In human terms, a king will gladly intervene to save his own people. A father does not hesitate to help his children. But God reveals much, much more of Himself. From the very beginning of His relationship with the Hebrew people, God informs us that He has a very different take on things.
Exodus 22:21 "Do not mistreat an alien or oppress him, for you were aliens in Egypt."Exodus 23:9 "Do not oppress an alien; you yourselves know how it feels to be aliens, because you were aliens in Egypt.
These are two short verses, but they say so much. First, God does not want His chosen people to act like other people. They were oppressed in Egypt, other nations oppress foreigners in their midst, but the Hebrews are to treat the alien as they would another Hebrew. In Exodus 12, as the Hebrews prepare for the Passover, the Hebrews are explicitly told to allow aliens among them to participate so long as the household is circumcised. Presumably, these Exodus 12 aliens were other enslaved peoples, but it may have also have referred to Egyptians. God is not vindictive and is not interested in setting up another system like the one from which He will deliver the Hebrews. The Hebrews are to act differently.
These verses also imply a kind of parallel relationship between God and the Hebrews, and the Hebrews and aliens. God extended His kindness and mercy to the Hebrews, they should extend it to the aliens. God desires that the world should see the behavior of the Jews towards foreigners, and, knowing that the Jews were themselves saved from an oppressive foreign power, understand that the Lord extends the same salvific embrace to them as well. God has helped the Hebrews. The Hebrews help us. God will help us. The way the Jews are to treat the foreigner, the alien, the oppressed and powerless, is meant to speak to those people in a way words could never express. It is an invitation-in-action to relationship with God, who is just and merciful.
This point is underscored by Exodus 22:22-15. Do not take advantage of the widow, the orphan or the poor. If you are in a position of power you must deal justly with them because God is compassionate! It was compassion that was displayed to the powerless Hebrews in bringing them out of Egypt and it is compassion that they are to show to the powerless. They must enact God's compassion as a message both to each other and to outsiders. There is no boundary, no us and them. And it is precisely Israel's failure to do this that so inflames the prophets.