The full night of learning on Shabuot night is an intensely personal experience, a time of spiritual renewal. One of the names of Shabuot, Hag Habikurim, the Festival of the First Fruits, refers not only to the offering of the first fruits or the two loaves offered on Shabuot, but also to the spiritual rejuvenation of Shabuot. On that uplifting day, exhausted individuals are given a new lease on life. The student who earlier had access only to the surface of Torah wisdom now finds, as a result of his exertion in Torah on this night, a new vitality to penetrate beyond superficial explanations.
Not only students of Torah, but the Torah itself is renewed on this night. While the Written Torah is fixed and definite, the Oral Law with its constantly growing and developing explanations and insights knows no limits. Torah is called the Es Hahayim, the Tree of Life, because it bears new fruits of intellect and reason every year, which consequently offers humanity an ever-fresh bounty of new perceptions and applications. Shabuot is indeed a "New Year" for the produce of the intellect.
Just as our material fortunes are decreed on Rosh Hashanah on the basis of our actions of the past year, and in particular of our service of that day, so also is our intellectual growth for the coming year. The Torah thoughts we will be granted to innovate are determined on Shabuot, the "New Year" of Torah. It is therefore critical that we have the merit of a night of intensive Torah study to prepare us for this momentous day. (The Three Festivals)