Translation by Rabbi Micha Berger click here for full introduction
In my opinion, this whole concept is included in Hashem’s mitzvah “Be holy, [for I am Holy].”3 The Midrash (Leviticus, Emor, ch. 24) says about this verse: “Can it [truly] be ‘Like Me?’ This is why it continues, ‘for I am Holy’ to teach that My Sanctity is above yours.” And about the foundation of this mitzvah of sanctity the Toras Kohanim4 has “‘be holy’ – be separate”. Nachmanides, in his commentary on the Torah, explains at length this notion of separation as it is stated in this mitzvah, that it is separation from excessive comfort and pleasure – even if they are actions that are not prohibited to us. In one illustrative statement, he writes that it is possible for a person to be disgusting with [what would otherwise be] the permission of the Torah, see his holy words there.
According to this, it would seem the Midrash is incomprehensible. What relevance does the concept of separation have to being similar to the Holy? The verse tells us with regard to this that His Will is not like this. As it says, “Can it [truly] be ‘Like Me?’ This is why it continues, ‘For I am holy’ to teach that My sanctity is higher than yours.” It is more difficult to understand “My sanctity is higher than yours.” This explanation is incumbent upon us to understand – in truth there is some similarity in the holiness He expects of us to His [Holiness], except that His Holiness is more general and inclusive. If we say that the essential idea of the holiness He demands of us (in this mitzvah of “be holy”) is distance from the permissible, that kind of holiness has nothing to do with Him.5