By Rabbi Larry Tabick, May 12, 2016
Kedoshim is sometimes called the Holiness Code, because holiness is a key concept within this sidrah. This holiness takes on a decidedly ethical tone, as in this verse, though there is ritual, too. At the level of peshat, the plain meaning, this text is clearly about kindness towards strangers.
In rabbinic literature, this principle was applied to converts to Judaism.