וְהִ֨תְקַדִּשְׁתֶּ֔ם וִהְיִיתֶ֖ם קְדֹשִׁ֑ים כִּ֛י אֲנִ֥י יְהוָ֖ה אֱלֹהֵיכֶֽם׃
Sanctifiez vous et soyez saints, car je suis l’Éternel votre Dieu.
Rashi
והתקדשתם SANCTIFY YOURSELVES — This implies keeping aloof from all idolatry (Sifra, Kedoshim, Chapter 10 2).
Alshekh
You shall sanctify yourselves. You should begin to purify yourselves and I promise you that I will assist you and you will be holy, and the “leaven in the dough” [the evil inclination] will not impede you.
Sforno
והתקדשתם, by staying clear of all incestuous relationships.