In the Torah portion, we are commanded not to aggrieve converts and to treat them appropriately, because “you were strangers in the land of Egypt.” The Sages liken the convert joining the Jewish people to an undomesticated animal that, of its own volition, joins a farm of domesticated animals, and is therefore worthy of abundant love.

“The Lord protects strangers” (Psalms 146:9). The Holy One, blessed be He, loves converts very much. To what is this matter comparable? It is comparable to a king who had a flock that would emerge and graze in the field and return to the pen each evening. One time, a deer joined the flock. It went near the goats and the sheep and was grazing with them. It entered the pen with the flock. When the flock would go out to graze, the deer went out with it. The shepherds told the king: The deer goes with the flock and grazes with them. Each day, it goes out and enters with them. The king loved the deer very much. When it went out to the field, he would command the shepherd, saying to him: Be careful with this deer, and ensure that no man will strike it. When it entered with the flock, he would command his beloved in its regard: Give it to eat and drink. He loved the deer very much. The shepherd said to him: My master, the king: You have so many male goats, and so many female goats, and so many sheep, and so many kids, and you do not caution me to protect them, but the deer, you command me every day concerning it. The king said to him: As for the flock, it is its manner to graze. But deer, they live in the wilderness, and it is not their manner to enter the settled area, among the people, and this deer entered and lived among us. Shouldn’t we give it credit that it left the great, broad wilderness, a place where the male and the female deer graze, and left them and came to us? Therefore, we must give it credit. So too, the Holy One, blessed be He, said: I must give great credit to the convert, who left his family and his father’s house, and came to Me. Therefore, I command concerning him: “You shall love the stranger” (Deuteronomy 10:19); “You shall not mistreat and you shall not oppress him” (Exodus 22:20). That is why it is stated: “The Lord protects strangers” (Psalms 146:9). (Midrash Tehillim [Buber] 148)