One of the defining characteristics of God is His justice. He does not show partiality to any one person above another, even if it may seem like He does because of His selection of Israel as His chosen people. God still has His eyes towards other people.
As proof of this, Moses couples God’s power and majesty and might with His care and concern for those who can’t take care of themselves. As powerful as God is (Deuteronomy 10:17), He takes care of the lowliest among mankind (Deuteronomy 10:18).
By itself, this is an argument for servant leadership. One can’t hope to lead others unless they take care of everyone equally. God is above bribes, and so must every true leader. Justice for everyone includes justice for anyone.
But then God flips this statement around by way of a direct command. He tells Israel to “show your love for the aliens”—not little green men, mind you, but foreigners who happen to dwell amongst them.
Why? Because they know what it’s like to be foreigners.
It’s remarkable that even after four hundred years in a different country, Israel could still be seen as an “other.” That shows the decline over their history; initially, Joseph was second in command, but over time, they fell all the way down the social ladder.
This experience should have shaped their interactions with those who are hoping to become a part of the Israelite camp. Since they knew how it felt to be outside the main body of people, they should treat others with kindness.
Moses has brought this up before. In Exodus 23:9, he told them to “not oppress a stranger, since you yourselves know the feelings of a stranger, for you also were strangers in the land of Egypt.”
That’s the difference between empathy and sympathy. If I’m sympathetic towards someone else, I can show compassion on an intellectual level. I recognize someone is in distress and will help how I can.
There’s nothing wrong with that, but empathy is so much stronger. The fact that you are willing to share in someone’s pain with them, to go through the trials by their side, either because you have been there before or care for them as you would your own soul, is powerful. It creates bonds, which can stay intact long after the experience is over.
God wanted Israel to not only have sympathy for foreigners, but to empathize with them because of their shared experiences. If they took that posture towards others, Israel wouldn’t feel so exclusive, and others would come to know their God.