Is the Mitzvah of Kedoshim Tihyu considered one of the 613 Mitzvos?
Must one sanctify himself with the permitted?
Talmudic ruling: Rava states in the Talmud that one is to sanctify himself with that which is permitted.
Ruling in Rishonim: Some Poskim rule it is a Biblical positive command to do so. Others rule there is no Biblical positive command to do so. Even according to the above Poskim who rule there is no Biblical command to do so, some of these Poskim rule there is a negative command against doing that which is permitted simply out of pursuit of pleasure.
Ruling in Poskim: In the Shulchan Aruch the Michaber rules it is a mere act of praise and piety to do so, and one who does not do so is merely not praised, implying there is no Biblical transgression involved. However even the Michaber ibid concludes that one is obligated to limit what he does so that it be only for the sake of Heaven. The Alter Rebbe rules in Tanya that it is a Biblically command, and even according to those who argue it is at the very least a Rabbinically command. The accepted ruling of Chassidus, as is evident from various talks of the Chabad Rabbeim, is that it is a Biblical command.
Effect of this Avoda and its connection to the redemption: The service of sanctifying oneself with the permitted has special connection with the future redemption, and it draws down an even higher level of Elokus than Torah and Mitzvos. Torah and Mitzvos don’t completely nullify the person and only relate to the person externally. However the service of sanctifying oneself with the permitted completely permeates the essence of the person and brings him to a complete state of Bittul. This service of Kadesh Atzmecha is responsible for drawing down the great revelations of the redemption, in which the Tzaddikim are called Kadosh.
 Sefer Chareidim 20:13 in name of Rabbeinu Shlomo Ivan Gavriel [Rashbag] that he lists it as one of the 613 Mitzvos.
 Omitted in Rambam; Chinuch and other Monei Hamitzvos
 Yevamos 20a
 Ramban ibid; Chareidim 20:13 in name of Rabbeinu Shlomo Ivan Gavriel [Rashbag]
 Omitted in Chinuch and Rambam and others from their list of positive commands.
 Chinuch 387 based on verse of “Lo Sasuru Acharei” learns it is a negative command; Rambam Lo Sasei 47; Mentioned in Kuntrus Eitz HaChaim; Vetzaruch Iyun if they learn that every act of self-indulgence is deemed as a transgression of this negative command, or only a constant pursuit of pleasures transgresses this command. The wording in the Chinuch is “One who constantly pursues the pleasures of the world out of pure lust constantly transgresses this command, each time he indulges in the pleasure”.
 Chapter 231
 Chapter 27 and 30
 Kuntrus Eitz HaChaim; Likkutei Sichos 1:254-256 “The Mitzvah of Kadesh Atzmecha is not just a Hiddur Mitzvah and the like, but a positive command in the Torah”
 Mamar Shavuos 5717 [printed in Toras Menachem 20:35]