Tafsiran Bilangan 7:12: Rashi, Kli Yakar, Or HaChaim & Tur HaArokh

ביום הראשון ON THE FIRST DAY — That day received ten crowns (was distinguished in ten different ways): it was the same day as was the first day of Creation, the first day on which the princes offered etc., as it is set forth in Seder Olam 7 (cf. Rashi on Leviticus 9:1 and Note 2 thereon).

“And it was the one who offered on the first day, etc.” This section is connected to the Priestly Blessing which concludes all blessings with peace, for if there is no peace, there is nothing. Therefore, peace comes at the final conclusion and is most beloved, because all the preceding [blessings] appear as if they are still lacking until the arrival of the blessing that follows them, which comes to fill what the first blessing was missing. But the final [blessing] lacks nothing because there is no need for any additional blessing to come after it to fill its deficiency. Therefore, the Midrash praises and says, “Great is peace for it seals all blessings,” as this indicates the deficiency of the preceding blessings and the excellence of the conclusion. The creation of man at the end proves this point, and therefore there are many midrashim that speak of the virtue of peace, which is necessary for both the lower and upper worlds.
They further said (Bamidbar Rabbah 11:7), “Great is peace, for even the dead need it, as it is said And you shall come to your fathers in peace (Genesis 15:15).” The explanation is not that there is some quarrel or dispute among the dead that requires peace, but rather the dead need there to be peace among the living. For if there is no peace among the living and they insult one another, their words will quickly run to insult both the living and the dead, to the point that even those who dwell in the dust have no rest in their graves due to the quarrelsome tongues of the living. This is like the incident of the woman who was buried in a reed mat (Berakhot 18b), and like what happens every day in our generation. Therefore, the dead need there to be peace among the living, and then they will rest in peace on their resting places.

המקריב ביום הראשון, the one who presented (his gift) on the first day, etc. Why did the Torah have to write the words את קרבנו, (what else did he offer)? Perhaps the Torah wanted to emphasize that the princes each paid for these sacrifices (gifts) out of their own pockets. It was not paid for by the respective tribe's treasury. Sifri item 48 derive this from the repetition of the words: "this was the offering of so and so," after each report of the prince who offered his sacrifice. The reason the Torah also wrote קרבנו, "his offering," before listing the nature of the offering is because the offering consisted of two aspects. 1) acknowledgment of the exceptional merits of the prince bringing the offering; 2) the offering itself. Bamidbar Rabbah 13,10 extols Nachshon's merits for instance, telling us details of his accomplishments. The words הקריב את קרבנו mean that in addition to the visible aspect of the offering there was an invisible aspect, i.e. the devotion to G'd of the person offering the gift. It is well to remember that whenever a person offers an offering to G'd as a gift, such an offering is accompanied by the forces of sanctity which surround such a person. Moreover, it is the nature of the offering to activate various "branches" of sanctity. Our verse testifies that Nachshon succeeded in "offering his sacrifice," i.e. to imbue it with the "sparks" of sanctity and to thereby accomplish all that it is possible to accomplish by means of such a gift-offering.

למטה יהודה [NACHSHON THE SON OF AMINADAB,] OF THE TRIBE OF JUDAH — By these words Scripture merely states his genealogy after his tribe, and they do not mean that he collected the offerings from his tribe and offered them on their behalf. Or perhaps it does state למטה יהודה only to intimate that he collected the offerings from his tribe and then brought them? Scripture, however, states, (v. 17): this was the offering of Nachshon — he brought it of that which was his own (Sifrei Bamidbar 48).