Musar על דברים 5:1

It is known that Torah study in itself (aside from learning leading to doing) is a positive commandment of the Torah, as it is written (Devarim 5:1): "And you shall study them (the mitzvoth) and you shall take care to do them."

Know - that the pious one (R. Yosef Karo) and I agreed to make a great effort on the night of Shavuot, and to keep sleep from our eyes. Praise to God, so it was. We didn't stop one moment - listen, and your soul will be revived...