Parashas Kedoshim · Passuk 19:02
Chabad.org — English translation + Rashi
Torah Temimah points to Toras Kohanim.
English: “You shall be holy” — you shall be separate [from immorality]. “For I am holy” — if you sanctify yourselves, I account it as though you had sanctified Me.
Kedushah as separation from arayos
Kedoshim follows the arayos of Acharei Mos: holiness begins with separation from forbidden relations. One who separates from ervah is called kadosh.