וידבר משה אל ראשי המטות וגו'...זה הדבר אשר צוה ה,“Moses spoke to the heads of the tribes of Israel....this is what the Lord has commanded.” When Rabbi Sh’muel son of Meir, a grandson of Rashi, was asked where we can find that the legislation concerning vows was commanded to Moses, he directed the questioner to what has been written in the Torah immediately prior to our portion, namely: “these are the rules concerning the festivals for the Lord, apart from your vows, etc. “(Numbers, 29 39) The reference is to free willed vows and free will offerings, etc. There is also another category of vows, which is discussed in the Torah. Our verse refers to the chapter 28 in Numbers which commences with rules concerning sacrificial offerings.