From Torah.org, "Rejoicing on the Holidays", Moshe Golderg: It is a mitzvah to celebrate the holidays (Pesach, Shavuos, and Sukkos) with meat, wine, fine clothing, and sweets. We should also help the poor and the lonely to rejoice.
The main focus of this mitzvah is to rejoice in the opportunity to perform mitzvos and to serve Hashem with joy (Rambam, Hilchos Sukkah 8:15).
The Sefer HaChinuch (mitzvah 488) explains that we need joy in our lives just as we need food and sleep. Thus, the Torah provides us with opportunities to rejoice so that even our rejoicing will be part of our avodas Hashem, as the Mishnah teaches: “Do all of your activities for the sake of Heaven” (Avos 2:17).
The Vilna Gaon explains that one should avoid all thoughts of worry, sadness, or pain throughout all the days of the holidays.
Ben: We are all God's children, So you should treat all people equally. So if you are happy and celebrating, you should invite the poor, the sad and lonely, even people who are happy but alone.
The Times of Israel Blogs, Chaim Navon, excerpt from "How and Why Should One Rejoice on Holidays: And while one eats and drinks himself, it is his duty to feed the stranger, the orphan, the widow, and other poor and unfortunate people, for he who locks the doors to his courtyard and eats and drinks with his wife and family, without giving to eat and drink to the poor and bitter in soul – his meal is not rejoicing in a divine commandment, but a rejoicing in his own stomach.
Torah MiTzion, Shlomo H. Pick Excerpt from- Rejoicing Before God: The common theme of all these rejoicings is that they are “before the Lord your God”. This is the characteristic of rejoicing in Judaism – it is before God. .......
Rejoicing on before the Lord is both an intellectual and existential experience. The intellectual experience is through studying God’s Torah, especially the laws of the festival. The existential experience is by praying and hosting God’s children, the converts, orphans, widow, the destitute and the embittered. When you do this, especially on the festivals, you are in effect in God’s house, standing and rejoicing before God.
comments: [email protected]
JewishLinks.news - The Holiday of Joy, Rabbi Dr. Avi Kuperberg: The Tanya emphasizes the mitzvah of being in a constant state of simcha. King David, in Tehillim, urges us to worship Hashem with joy. The Gemara (Shabbos 30b) underscores that the divine presence only rests upon those who are joyful. Celebrating yom tovim (festivals) with simcha is counted as positive mitzvah number 488 by the Michas Chinuch. This joy is not mere advice but a fundamental commandment.