Commentaire sur Les Nombres 29:39

אלה תעשו לה׳ במועדיכם THESE YE SHALL OFFER TO THE LORD ON YOUR APPOINTED FESTIVALS — as something that is laid down as a duty,

אלה תעשו לה' במועדיכם לבד מנדריכם ונדבותיכם, “these (offerings) you are to present for Hashem on your appointed festivals apart from your vows and free-will offerings, etc.” Actually, the Torah should have written: “your burnt-offerings and your peace-offerings” first, seeing these are offerings consisting of meat before switching to offerings which consist of meal-offerings and libations, instead of mentioning the most important offerings, i.e. the total (burnt) offerings only after the vows and free-will offerings. After all, our sages in Yuma 34 are specific about the burnt-offering always preceding other offerings and being the first offering presented on the altar each morning. The Torah concluded its list with the peace-offerings as the purpose of these offerings is להשלים המדות, “to strive to perfect one’s character traits” (compare author’s comments on Genesis 46,1). Moreover, it is the custom for the Torah whenever it enumerates a number of different offerings to conclude with the “peace-offerings.” Furthermore the greatest and concluding blessing of the priests is the blessing of peace, i.e. שלום. This then is the reason why here too the “peace-offerings” are mentioned last.
Just as the tetragrammaton had been associated with these offerings at the beginning of the chapter, the Torah also concludes with mentioning the fact that these offerings are addressed to Hashem. The Torah wishes to underline that all the offerings must always be addressed to this attribute and none other. The reason that the seventy bulls are mentioned between the beginning and the end of our chapter is to remind us that although they were offered on behalf of the seventy nations who are under the immediate care of their celestial representatives, the offerings were all addressed to the attribute Hashem, not to any underlings, angels, etc. The blessings which humanity enjoys from celestial sources are due to the seventy bulls offered to Hashem on behalf of the nations by the priests in the Holy Temple in Jerusalem. Each “force” in the terrestrial world must recognize that there is a “force” above it, until eventually the highest “force” Hashem is reached. This is the meaning of Kohelet 5,7: “for there is One higher than high Who watches and there are high ones above them.”

As obligations. Rashi wishes to answer the question: It is written, “These you shall make to Hashem on your festivals, aside from your vows…” However, since you also must make the vows and dedications, why did it not group them together? He answers that “these” which was written at the beginning [of the verse] refer to those things designated as obligations, aside from the dedications which are optional.