Musar sobre Números 28:26

It follows, then, that Pesach is the first of the Chagim, Shavuos, the second Chag and Sukkos the final Chag. That is why Shavuos is called the “Tree of Life that is in the midst of the garden” (Zohar, 3:96a), because it is the middle Chag [i.e., sandwiched between Pesach and Sukkos]. The Zohar also refers to Shavuos as the “praise of the Torah,” which is highest praise of all. That is why the Torah was given on this day, since the Torah is also called the “Tree of Life that is in the midst of the garden.” I believe that it was with reference to this that the Zohar states (ibid.): “And on the Day of the First Fruits when you sacrifice a new offering to Hashem in your weeks, there shall be for you a holy convocation” (Bamidbar 28:26). Rabbi Shimon began his address, “‘Then the trees of the forest will exult before Hashem, for He comes to judge the earth’ (Divrei HaYamim 16:23)… On the surface it is not clear why Rabbi Shimon chose to elaborate on this verse from Divrei HaYamim in this context. I believe that it is because all the trees of the forest of Levanon are bound to the “Tree of Life in the midst of the garden,” as I have already explained. In order to demonstrate His affection for Israel before all the nations the Holy One Blessed is He sustained us with manna in the desert. Thus is it stated, “Behold I will rain upon you bread from Heaven” (Shemos 16:4). He also commanded us to bring an offering of barley flour on the Yom Tov of Shavuos. Concerning this the Zohar (ibid.) teaches, “Meritorious is Israel’s lot, for the Holy One Blessed is He tests them with a barley offering, like a straying wife who must bring an offering of animal fodder. So, too, the Holy One Blessed is He commanded them to bring an offering of barley flour.