Food and Drink on Shavuos
1. Just as it is a mitzvah to honor Shabbos, so one must honor all festivals with culinary delights and treats. This is particular true of Shavuos, on which the Torah was given. ((See Pesachim 68b; Machazik Berachah 242:2.))
2. There is furthermore a mitzvah of joy on festival days, ((Shulchan Aruch, Orach Chayim 529:2-3.)) which is performed (for men) by the consumption of meat and wine. ((Ibid.; see also Biur Halachah 545, s.v. veim.)) Therefore, the custom to eat milky foods (see below) should not prevent one from eating meat. One may divide the meals between milky and meaty (milk at night and meat in the day).
3. Even though eating and drinking is a mitzvah, one should not spend the entire day in eating and drinking, as the verse states, “It shall be Atzeres for Hashem” (Devarim 16:8). Although the verse also writes that “It shall be Atzeres for you,” the Gemara resolves the contradiction by stating that it is “half for you, and half for Hashem.” ((Pesachim, loc. cit.)) One must therefore dedicate time to the study of Torah—in particular on Shavuos. ((See Kaf Ha-Chayim494:9.))
4. It is forbidden to fast on Shavuos, like other festivals. Some maintain that one may not fast even for a bad dream (taanis chalom), ((Kaf Ha-Chayim494:38, because of the special joy of Torah.)) but most authorities agree that it is permitted to fast on account of a bad dream. ((See Mishnah Berurah 429:19.))
Eating Milky Foods
5. It is customary to partake of milky foods on Shavuos. The principle reason for this is that one should partake of two dishes in commemoration of the “Two Breads” (shetei ha-lechem) offering of Shavuos. One therefore starts the meal eating dairy products, and mid-way through the meal, one removes the dairy products, and replaces them with meat products. Upon replacing the dairy products with the meat products, one is required to remove the bread eaten during the dairy portion of the meal, and replace it with bread that was not used with a dairy meal. ((See Shulchan Aruch, Yoreh Deah 89:4.)) By using two separate sets of bread, shtei halechem offering is commemorated. ((Rema 494:3; see, however, Iggros Moshe, Yoreh Deah 1:38, who notes that the prohibition to eat a meat meal with bread that was eaten with dairy products only applies to the smaller pieces of bread that might have come into contact with dairy products. The loaf of bread on the table may be used during the meat meal. If so, there is no need for two separate sets of bread. Nevertheless, although there is no obligation to remove the bread eaten with the dairy meal, it is certainly praiseworthy, and this might be sufficient to constitute a commemoration of the shtei ha-lechem offering.)) To ensure that a new loaf of bread is used for the meaty part of the meal, some bake milky bread. ((Mishnah Berurah 494:16; milky bread must be baked with a siman, a distinctive sign that reminds one that the bread is milky (and may not be eaten with or after meat).))
6. An additional reason for eating dairy products is that at the time of Matan Torah the Jewish people became obligated in all of the mitzvos of the Torah. As such, in order to eat meat, they would have had to follow the complex procedure involved in producing kosher meat. Because this procedure required time in order to properly prepare the meat, the only food items available immediately after Matan Torah (the giving of the Torah) were dairy products. This state of affairs is commemorated by the consumption of dairy products. ((Mishnah Berurah 494:12; however, see Shalmei Todah no. 2, who writes that if the Torah was given on Shabbos (see Shabbos 87a), the need to eat dairy products might be attributed to the prohibition of preparing meat on Shabbos rather than the giving of the Torah on Shavuos.))
7. A further reason for the custom is to highlight the difference between Israel and Divine angels. As guests at the table of Avraham Avinu, the angels were not particular to separate between meat and milk. When the angels claimed that the people of Israel were unworthy of receiving the Torah, G-d asked them: “Was it not you who descended upon Avraham and ate milk and meat together?” ((Midrash Tehillim chap. 8.)) Our meticulous separation of meat and milk demonstrates our worthiness of the Torah. ((Be’er Heitev 494:8; Mishnah Berurah 494:12-13; see also Beis Ha-Levi, Parashas Yisro, who writes that the angels did not actually mix meat and milk, but were rather not meticulous in the various laws pertaining to eating meat after the consumption of dairy products. Therefore, on Shavuot, the minhag developed to eat dairy products followed by meat. By doing so with the proper meticulousness, we show that we are not like the angels, and we are indeed worthy of receiving the Torah.))
8. Additional reasons: Milk is a symbol of purity, which the nation of Israel attains over the period of the Omer count; ((Magen Avraham 494:6.)) the gematria of chalav (milk) is forty, corresponding to the forty days that Moshe spent on Sinai to receive the Torah; ((See Orach Chaim, p. 247.)) the consumption of dairy products (and of honey) recalls the verse “honey and milk beneath your tongue” (Shir Hashirim 4:11), which is stated concerning Torah; ((Mishnah Berurah 494:13.)) before the Torah was given it was prohibited to drink milk, because it was considered a limb from a living creature (eiver min ha-chay). ((Moadim U-Zemanim 8:319.))
9. The regular laws of separating between meat and milk apply to the Shavuos meals. If meat and milk are to be consumed in the same meal, one should: 1) Eat the milk first; ((See Shulchan Aruch, Yoreh Deah 89:2.)) 2) Clear the table after the milk, or remove the tablecloth; ((Ibid. 4.)) 3) Wash out one’s mouth and eat bread or something that clears the mouth of milky residue; ((Ibid. 2.)) 4) One need not recite birkas hamazon (though some require it); ((Mishnah Berurah 494:16.)) 5) One must ensure that one’s hands are clean; ((Shulchan Aruch, Yoreh Deah 89:2.)) 6) Some state that one should wait half an hour. ((See Hagahos Maimoni to Rambam, Maachalos Assuros 9:28.))
Decorating the Synagogue
10. It is customary to spread out greenery (leaves and branches) in our homes and synagogue on Shavuos. ((Rema, Orach Chayim 494:3; an ancient source for the custom is found in Targum Sheini to Megillas Esther, 3:68, which describes the customs that Haman mentioned in depicting the Jews as being different from all others. One of the customs listed is the throwing of roses in synagogues on Shavuos.)) We may not prepare these during the Holiday itself, but only before; if they were not cut or prepared before the Holiday, it is forbidden to do it during the Holiday. ((In should be noted that the Vilna Gaon objected to this custom, because it has become the way of Christians to decorate their places of worship in this manner (see Chayei Adam 131:13 and Maaseh Rav, as mentioned also by Mishnah Berurah). However, the custom has remained widespread.))
11. Several reasons are given for this custom: 1) In order to recall the beauty of Mount Sinai, which was verdant and lush with green even though it was a mountain, as we learn from the Divine warning: “also your sheep and cattle should not graze by this mountain” (Shemos 34:3); ((Levush, ibid.)) 2) On Shavuos we are judged concerning the fruit of the trees, ((Mishnah, Rosh Hashanah 16a.)) and we must remember to pray that the trees grow well and healthy; 3) Moshe, who was born on the seventh day of Adar, was hidden by his mother for three months, until the sixth day of Sivan. He was then placed among the river weeds. We therefore spread greens to remember the miracle that was performed for Moses at that time; 4) The Midrash teaches us a parable. A king planted a garden. After some days, the king looked at the garden and found it full of thorns. He was about to destroy the garden, when he saw a rose blossoming in it. The king declared, “For the sake of that one rose, I will not destroy the garden!” So too, although the world is mired in sin and degradation, for the sake of the Torah, and for the sake of the Jewish People, whose purpose it is to fulfill the Torah, the world is not destroyed, but rather, the whole world is saved.
Staying Up for Studying Torah
12. A prevalent custom is to stay awake all night (until dawn) on the first night of Shavuos and study Torah. ((Mishnah Berurah 494:1, citing from Zohar.)) The principle reason for this is that at the time the Torah was given, our forefathers slept throughout the night. Hashem had to awaken the nation of Israel from their slumber so the Torah could be given to them. In order to “repair” this fault in our ancestors’ reception of the Torah, we stay the entire up immersed in the study of Torah. ((Magen Avraham 494.)) Kabbalists place great emphasis on the importance of this custom. ((See, for instance, Ben Ish Chai, Parashas Bamidbar, no. 3 (based on Shaar Ha-Kavanos of Ari).))
13. Some begin the night’s study session people with the recitation of Tikun Leil Shavuos, which consists of representative quotes from every section of the Torah—specifically from the Written Torah according to one Tikkin, ((Tikkun of the holy Ari.)) and including the Oral Torah according to another. ((Tikkun of the holy Shelah.)) But many people simply study any Torah they have the ability and knowledge to learn, and most people attend a lecture or dialogue session.
14. There are a number of halachos a person should be aware of when staying up the entire night. The following is a very brief summary: 1) Bedtime Shema: Shema should be read as on every night (preferably prior to midnight ((“Midnight” refers to the middle of the night according to the Jewish division, and not to 12:00am.)) ), but the blessing of hamapil should not be recited; 2) Morning Blessings (birkot ha-shachar): According to the Sephardi custom, one can recite all the Morning Blessings after midnight, ((Including Elokai Neshamah.)) with the exception of the blessings over Torah, which is recited after dawn. According to the prevalent Ashkenazi custom, the Morning Blessings are only recited after dawn, with the exception of Elokai Neshamah and Maavir Sheinah. These two blessings are recited out loud by one who has slept during the night, who is able to recite them both for himself and for all those who listen to his blessings. The same applies to the blessings over the Torah. However, is one slept on Shavuos eve (during the day), one may recited the blessings over the Torah for oneself. 3) Washing Hands (netilas yadayim): After dawn one should use the bathroom, following which one can wash netilas yadayim and recite the blessing.
15. The Scroll of Ruth is publically read on Shavuos morning (in Israel, many have the custom of the Reader reciting two blessings (Megillah and Shehecheyanu) before the reading). The simple reason for this is that King David was born and died on Shavuos, ((See Tosafos, Chagigah 17a.)) and we therefore read Ruth in order to honor King David by recalling his ancestry. Another reason is that just as the process leading to our receiving the Torah was filled with pain and trying times, so too the path that Ruth took to receiving the Torah was filled with the same. ((Magen Avraham 490:8.))
16. Because of the special connection of the day with King David, some have the custom to read the entire book of Tehillim on Shavuos. ((Ben Ish Chay, Bamidbar 6.))