A foreigner is one not native to a place or community. Whether one has come through migration or enslavement, he is a foreigner.
Treat All Of Mankind In A Manner That You Want To Be Treated
"When a foreigner resides among you in your land, do not mistreat them. The foreigner residing among you must be treated as your native-born. Love them as yourself, for you were foreigners in Egypt. I am the Lord your God (Leviticus 19:33-34).
God Is No Respecter of Persons (Romans 2:11), Neither Should We Be