The Mishnah does not mention whether Nesachim were brought with the Korbanos
(the Olos and Shelamim) that were offered by the Nesi'im (as described in
Bamidbar 7:10-88). This is presumably because it is not relevant in
practice, but only as a historical note. It seems, though, that according to
the rule of the Mishnah, the Nesi'im were required to bring Nesachim with
their Korbanos. There are various opinions regarding whether or not they
indeed brought Nesachim.
(a) RASHI in Shir ha'Shirim (5:1) explains that the verse there refers to
the Korbanos that the Nesi'im brought at the time of the dedication of the
Mishkan. Rashi there adds that when the verse in Shir ha'Shirim says, "I
drank my wine," it is referring to the Nesachim. The PARDES YOSEF (Bamidbar
15:2) says that it is clear that Rashi holds that the Nesi'im brought
Nesachim with their Korbanos.
(b) The SEFORNO (Bamidbar 15:3) states that, historically, there were three
stages of bringing Nesachim. The first stage was when the Torah was given,
at which time no Nesachim were supposed to be brought. After the sin of the
Egel ha'Zahav, Hashem required that Nesachim be brought with Korbenos
Tzibur, public offerings, as a partial atonement for the sin. After the sin
of the Meraglim, Hashem required further that Nesachim be brought with
Korbenos Yachid, private offerings, as well.
Although the Seforno does not address whether or not the Nesi'im brought
Nesachim, we can infer that since the Korbanos of the Nesi'im were private
Korbanos that were brought before the sin of the Meraglim, the Seforno would
hold that they did not bring Nesachim.
However, according to the approach of the NETZIV in HA'EMEK DAVAR (Bamidbar
7:15), it is possible that the Seforno agrees that the Nesi'im did bring
Nesachim. The Netziv explains that although the Korbanos of the Nesi'im were
brought by individuals, they had the status of Korbenos Tzibur. To prove his
point, he says that had they had the status of Korbenos Yachid, they would
not have been able to be brought on Shabbos. We know, however, that they
were brought on Shabbos, since they were brought for twelve consecutive
days.
We find also that the Seforno earlier (Bamidbar 7:2) says that the reason
why the Nesi'im brought these Korbanos was because each Nasi felt that "some
members of his Shevet were suspected of sinning." Since the Nesi'im were the
leaders of the Shevatim, they decided to bring Korbanos to atone for their
Shevatim. This implies that their Korbanos were considered to be Korbenos
Tzibur, and thus warranted having Nesachim brought with them.
However, the Midrash Rabah (Bamidbar 14:2) seems to dispute this. The Nasi
who brought the Korban on the seventh day was Elishama ben Amihud, the
leader of Efrayim. The Midrash says that Hashem declared, "Yosef, you kept
the Shabbos before the Torah was given! Therefore, by your life, I shall
reward your grandchild, allowing him to bring his Korban on Shabbos, which
others may not do! " If the Korbanos of all of the Nesi'im had the status of
Korbenos Tzibur, then any Nasi's Korbanos could have been brought on
Shabbos! Since the Midrash says that the Korbanos of Yosef's descendant
differed from all other private Korbanos, it seems that the Midrash
maintains that the Korbanos of the Nesi'im were private Korbenos Yachid. The
allowance to bring the Korbanos on Shabbos was a Hora'as Sha'ah. The ARUCH
LA'NER (Yevamos 6a) also says that it was a Hora'as Sha'ah that allowed
Elishama ben Amihud to bring his Korbanos on Shabbos.
According to the Midrash, which maintains that the Korbanos of the Nesi'im
were Korbenos Yachid, it seems that Nesachim were *not* brought with the
Korbanos. (However, it could be that just as there was a Hora'as Sha'ah
permitting the Korbanos to be brought on Shabbos, there was also a Hora'as
Sha'ah commanding the Nesi'im to bring Nesachim.)
(c) The RAMBAN (Bamidbar 15:2) explains that the Nesi'im did *not* bring
Nesachim, because in the Midbar the Nesachim were brought only with a Korban
Tamid (possibly including other Korbenos Tzibur).
The NETZIV in HA'EMEK DAVAR (Bamidbar 7:15) has difficulty with the Ramban's
explanation. How can the Ramban say that Nesachim were not brought with the
Korbanos of the Nesi'im? When the verse summarizes the number of the animal
offerings brought by the Nesi'im, the verse states, "u'Minchasam" -- "and
their Menachos" (Bamidbar 7:87). We know that the term "Menachos" includes
Nesachim. This clearly implies that the Nesi'im brought Nesachim!
The Netziv, however, concludes that this assumption is not necessarily true.
When the Torah says that they brought the Menachos together with the
Korbanos, it may mean that they brought flour and oil offerings, without
wine (Nesachim). (Y. Montrose)