שמור את חדש האביב ועשית פסח ... ועשית חג שבועות לד' אלקיך ... ושמחת לפני ד' ... חג הסוכות תעשה לך שבעת ימים ... ושמחת בחגך ... והיתה אך שמח
The Baal HaTurim notes that with regard to the Yom Tov of Pesach, the Torah does not mention the mitzvah of simchah, joy. Concerning Shavuos, the Torah mentions simchah once, while regarding Succos, the Torah mentions it twice. He explains that, on Pesach, the crops are still growing in the field. Nothing has been harvested. Understandably, the farmer is (the Jews lived an agrarian lifestyle) nervous, hoping that he will be blessed with a good yield. Until that takes place, however, he is a bundle of nerves. The Torah does not compel him to rejoice. We have a mitzvah of…