“To be a Jew is to be a stranger. It is hard to avoid the conclusion that this is why Abraham is commanded to leave land, home and father’s house; why, long before Joseph was born, Abraham was already told that his descendants would be “strangers in a land not their own”; why Moses had to suffer personal exile before assuming leadership of the people; why the Israelites underwent persecution before inheriting their own land; and why the Torah is so insistent that this experience – the retelling of the story on Pesach, along with the never-forgotten taste of the bread of affliction and the bitter herbs of slavery – should become a permanent part of their collective memory.”
. . .
“Why should you not hate the stranger? – asks the Torah. Because you once stood where he stands now. You know the heart of the stranger because you were once a stranger in the land of Egypt. If you are human, so is he. If he is less than human, so are you. You must fight the hatred in your heart as I once fought the greatest ruler and the strongest empire in the ancient world on your behalf. I made you into the world’s archetypal strangers so that you would fight for the rights of strangers – for your own and those of others, wherever they are, whoever they are, whatever the colour of their skin or the nature of their culture, because though they are not in your image – says G-d – they are nonetheless in Mine. There is only one reply strong enough to answer the question: Why should I not hate the stranger? Because the stranger is me.”
http://rabbisacks.org/covenant-conversation-5768-mishpatim-loving-the-stranger/
Bearing Witness in America 