Moses then reviewed with the Jewish people the laws of the three “pilgrim” festivals – Passover, Shavu’ot, and Sukot – which they were required to celebrate in the Temple-city.
Celebrating Life
וְשָׂמַחְתָּ בְּחַגֶּךָ וגו': (דברים טז:יד)
[Moses told the Jewish people,] “You must rejoice in your festival.” Deuteronomy 16:14

Rabbi Shneur Zalman of Liadi, the founder of Chabad Chasidism, interpreted this phrase as follows.

“You should internalize the inner message of the festivals. This will infuse joy into your observance of the festivals; they will become your own, personal celebrations.”1