The 170th prohibition is that all members of the tribe of Levi are also forbidden from taking part of the spoils of war which were taken when Israel was being conquered.
The source of this mitzvah is G‑d's statement1 (exalted be He), "The Levitical priests and the entire tribe of Levi shall not have a portion and an inheritance." The Sifri explains, "The word 'portion' refers to spoils of war. The word 'inheritance' refers to the land."
It is possible for you to question me as follows: "Why did you count these two prohibitions — against taking a portion of the land and against taking part of the spoils — as separate mitzvos? They are included in one statement, and you already explained before2 that a lav she'b'klalus (inclusive prohibition) counts as one single prohibition!"
You must realize that Scripture itself separates the one prohibitive statement into two [in the next verse],3 "And he shall not have an inheritance." They are therefore two separate prohibitions with two separate names: the verse, "The Levitical priests ... shall not have a portion and an inheritance," which prohibits taking part of the spoils, and the verse, "And he shall not have an inheritance," which prohibits taking a portion of the land.
Both parts of this prohibition are repeated regarding the kohanim4 when G‑d (exalted be He) said to Aaron, "You shall not have any inheritance in their land, and you shall not have a portion among them." Our Sages explained5 that "You shall not have any inheritance in their land" refers to when the land was split up; "you shall not have a portion among them," refers to the spoils.
Perhaps you will think that these two prohibitions mentioned regarding the kohanim should be counted as two additional mitzvos. However, you must realize that since the prohibition is stated in general terms — "the entire tribe of Levi" — the kohanim are included. The prohibition was repeated regarding the kohanim for additional stress. The same applies wherever both the general law and a particular application are mentioned. The repetition is either to add stress or6 to complete a law which was not fully described in the one prohibitive statement.
If we would count G‑d's statement to Aaron, "You shall not have any inheritance in their land, and you shall not have a portion among them," as another prohibition in addition to, "The Levitical priests ...", we would similarly have to count the prohibitions of a kohen gadol to marry a divorcee, a chalalah, and a zonah as three more prohibitions in addition to the three which apply equally to all kohanim, whether kohen gadol or regular kohen.
And if someone will counter, "Yes, you should count them separately," we will answer that accordingly, a kohen gadol who marries a divorcee would transgress two prohibitions — one because any kohen may not marry a divorcee, and a second because a kohen gadol may not marry a divorcee. But the Gemara explains in Kiddushin7 that he only transgresses one prohibition. Therefore, it is clear that only the general prohibition is counted, and all other particular prohibitions associated with it come only to teach some particular detail or to complete the law, as we explained in Prohibition 161.8
In this same category belongs the prohibition to the kohanim not to "shave off patches of hair from their heads, nor shave the edges of their beards, nor make gouges in their skin."9 These three prohibitions were already said to the Jewish people in general: "Do not cut off the hair on the sides of your head and do not shave [the edges of your beard];"10 "Do not make a bald patch in the middle of your head for the dead;"11 and "Do not make gashes in your skin."12 They were repeated regarding the kohanim to completely describe the mitzvah, as explained in the end of tractate Makkos,13 where these three laws are explained. If these prohibitions were counted separately for kohanim and were not just given to completely describe the mitzvah, then a kohen would get two sets of lashes — one for being a Jew and one for being a kohen. But this is not the case; he gets one set of lashes just as any Jew would, as we explained in the proper place. You should understand and know this principle.