One must make an Eiruv Tavshillin on this day in order to permit cooking on Friday for Shabbat. One should take a complete challah (or roll) and a cooked portion of food and recite the text and blessing of the eiruv (page 327 in the new Chabad Siddur).  One who is making the eiruv on behalf of the community should have someone else pick up the food used for the eiruv and say the text printed in the Siddur (Ani mezakeh).

For the cooked food, one should use a piece of fish, chicken or an egg.

On Friday, the food should be prepared in such a way that it is all edible before Shabbat begins.

The food and challah which one put aside should be kept separate and not eaten until Shabbat begins.

It is preferable to use the challah of the eiruv for Lechem Mishnah on Friday night and on Shabbat day and then to eat it on Shabbat day for the third meal. This follows the principle that if an object was used for a mitzvah, it should be used again for another mitzvah.

One who did not eat the matzah or food on Shabbos has still fulfilled the mitzvah of eiruv.

One who forgot to make the eiruv may be able to rely on the eiruv made by the rabbi of the community as follows:

One who will be a guest for both eating and sleeping at someone else’s house need not make his own Eiruv Tavshilin as he is considered to be a member of his host’s family. Some say that he should make his own eiruv but without a bracha. (See Piskei Teshuvot, 527:17).

However, one who does not plan on cooking on Friday but is planning to light Shabbat candles should make an eiruv without a bracha.

If a child’s birthday is between Lag Ba’Omer and Shavuot, the Chabad custom is to postpone the Upsherinish (first haircut when a boy turns three) to Erev Shavuot.

Igrot Kodesh vol. 12, page 441

It is customary in many communities to decorate the synagogues and homes with greenery and flowers to commemorate the joy of the Giving of the Torah at which time Mount Sinai was covered with foliage and greenery.In addition, it is customary in many communities to put trees in the synagogues and homes. This reminds us that we are judged regarding fruits of the tree on this holiday and that we must pray in this regard.  Some say that this custom should not be followed as it is reminiscent of the holiday of a different religion.

Flowers are not considered muktzah as they have been designated for decorative use. One may not, however, put them into water on Yom Tov as this may cause them to open. This would be considered akin to planting. One may, however, add water to a vase  that is already in use. On Shabbat, one may not even add water.

Rama 494:2 and Mishna Berurah 10 in the name of the Gra. See Ex. 34:3,  Shulchan Aruch HaRav, 494:5 and 336:18

One should remember to provide the necessities of the holidays for those in need. Sufficient support should be provided so that the poor have enough to make Yom Tov in a comfortable and enjoyable manner. This is especially important regarding the holiday of Shavuot, which is only two days long and whose needs may therefore be overlooked. This Mitzvah benefits both the giver and the recipient.

Maimonides (Laws of Yom Tov 6:18) writes: “When a person eats and drinks [in celebration of a holiday], he is obligated to feed converts, orphans, widows, and others who are

destitute and poor. In contrast, a person who locks the gates of his

courtyard and eats and drinks with his children and his wife, without

feeding the poor and the embittered, is considered to be not rejoicing

with a mitzvah, but rather to be rejoicing with his belly.”

It is especially important to provide for Torah scholars and other righteous poor people who refrain from asking for help.

Torat Menachem, 5743, vol. 3:1536, Kaf HaChaim, 529:42, Sefer HaSichot, 5750, vol. 2:481, note 38

Shavuot, 6 and 7 Sivan, Thursday night, May 28– Motzei Shabbat, May – 30)

For this reason, the Chabad Rebbes would tell stories of the Baal Shem Tov on Shavuot.

 Sha’arei Teshuvah 494:7, Yalkut Shimoni 735, HaYom Yom, 7th of Sivan, Sefer HaSichot 5704, 140

The blessings on the candles are: Lehadlik ner shel Yom Tov and She’hechiyanu.

The evening service begins with Shir Hama’alot (page 161 in the new Chabad Siddur) and includes the Holiday Amidah (page 331).

Even those who customarily accept Shabbat and Yom Tov early should refrain from doing so on Shavuot in order to have a complete 50 days of the counting of the Omer (Mishnah Berurah 494:1).

The holiday Kiddush is on page 329.

Grace after meals includes Ya’aleh Veyavoh (pg. 92) and the Harachaman recited on a Yom Tov (pg. 95).

It is customary for men to remain awake and study Torah during the entire first night of Shavuot. As the Zohar, Parshat Emor, says “The early Chassidim would not sleep on this night. Rather they would study Torah.” This is to rectify the mistake of the Jews who overslept on the day of the receiving of the Torah (Magen Avraham 494:3), and to help us prepare to receive the Fiftieth Gate of Understanding on the day of Shavuot. (Zohar ibid)

If one stayed up the entire night and is afraid that he may be unable to concentrate on his prayers, it is better that he nap for a few hours before praying (Sha’arei Halacha UMinhag, 1 pg. 110).

In this case, one should recite the morning Shema before going to sleep.

The Lubavitcher Rebbe encouraged every Jewish man and woman to be present for the reading of the Ten Commandments. Parents should bring their children. Even babies (above the age of 30 days) should be brought (health permitting). (Sha’arei Halacha UMinhag 2, pg. 168, Likutei Sichot, 23:251 and 256. See  Likutei Sichot, ibid, pg. 251 that those who want may bring babies even younger than 30 days old.

The Haftorah of this day is referred to as “The Chariot of Yechezkel.” Due to the holiness of this haftorah, it is customary that a great person who is a Torah scholar read it. According to some customs, if a congregant reads the haftorah along with the Ba’al Maftir, he should stand up while doing so (Shulchan Aruch HaRav ibid, 6).

In Israel, where there is only one day of Yom Tov, Yizkor is recited on this day.  The same is true of Megillat Rut for those who customarily read it.

It is customary to eat dairy foods on Shavuot. There are many reasons given for this. (See ibid, 16.)

Among them:

1) After the giving of the Torah at Sinai, the Jewish people did not have kosher utensilsor kosher meat, so instead of taking the time to slaughter and salt the meat etc., they ate a dairy meal ( Mishnah Berurah, 494:12).

2) A variation of the same explanation is that since the Torah was given on Shabbat, they were not allowed to slaughter the animals and otherwise prepare them for eating (Ta’amei HaMinhagim in the name of Ge’ulat Yisrael).

3) The two breads that one has with the two meals (the original custom was to eat dairy and meat meals, both of which includedbread, see below) is reminiscent of the two loaves that were part of the Shavuot sacrifice (Rama, 494:3).

4) Milk represents purity. Milk is produced by the body from blood, and blood is associated with the impurity of Niddah (the blood of the menstrual cycle). Thus, consuming dairy represents the Jewish people being purified from the tuma (impurities) of Egypt (see Zohar Parshat Emor, 97b).

5) The whiteness of milk represents G-d’s pure loving kindness. The Torah was given to us out of G-d’s boundless kindness (Benei Yissachar, Chodesh Sivan 4:5).

6) One of the six names of Mount Sinai is Gavnunim (see Bamidbar Rabbah, 1:8 and Tehillim, 68:16) which is similar to the word gevinah – cheese. (Tamei HaMinhagim, page 281 in the name of Rav Shimshon of Ostrapolyah). See also there, page 279 that the name Sinai alludes to the sneh (thorn bush) in which G-d first revealed Himself to Moshe. This occurred on Mount Sinai. Indeed, there is a tradition that the stones from Mount Sinai have the image of a thorn bush inside of them. No matter how many times they are broken, this image appears.

7) Since milk comes from a living animal, it was actually not kosher until the giving of the Torah as it was considered eiver min hachai (part of a living animal). Since the laws of eiver min hachai are part of the Noahide code, the Jewish people were not allowed to consume milk at that time. It was permitted by the Torah which praises the land of Israel as the land of milk and honey. We commemorate this by eating dairy on this day. (See Bechorot, 6a based on Exodus, 3:8 and many other verses and Ta’amei HaMinhagim, in the name of Rav Nachum Ahron Roke’ach.)

In addition to the dairy meal, one should eat a meat meal on Shavuot day as one should doon every Yom Tov (see Shulchan Aruch HaRav 529:4).

The best way to accomplish both of these concepts is to first eat a dairy meal (or kiddush), recite the grace after meals, wait a half hour or an hour and then have a meat meal (Rama 494:3 Shulchan Aruch HaRav ibid See Y.D. Siman 88 and 89 with the commentaries).

The main halacha is that one need not recite the grace after meals between eating dairy and meat. It is preferable, however, to do so (see Pri Megadim, Siftei Da’at, Y.D. 89:16. See also, Zohar P. Mishpatim, 125a, quoted in Shach 15 on Y.D. ibid).

The candles should be lit from a pre-existing flame.

When lighting, one should be careful not to wave out the match, but rather to put it down and allow it go out by itself.

The candles must be lit on time as once Shabbat begins it is forbidden to light.

Those who say Yizkor should light a 24-hour candle at this time (from a pre-existing flame).

The Bracha of She’hechiyanu is recited at candle-lighting by the women or at Kiddush by the man who recites the Kiddush.

In many communities the Book of Ruth is read publicly without a beracha (Shulchan Aruch HaRav, ibid, 13 and 470, 17) on the second day of Shavuot before the Torah reading.

Chabad custom is not to read it publicly. It is read privately as part of the Tikkun. Sefardim and various Polish Chassidim also do not read Megillat Rut publicly (Otzar Minhagei Chabad, Sivan, page 305 and 306).

Many reasons have been given for the reading of this book on Shavuot. (See Sha’arei Teshuvah ibid, 7, Shulchan Aruch HaRav 494:13 and Ta’amei HaMinhagim). Several of them:

Those that follow the custom of the Vilna Gaon read this from a scroll and say a blessing before doing so (Mishnah Berurah, 490:18).

See Piskei Teshuvot 490, note 23 that the Vilna Gaon would also recite shehechiyanubefore reading Megillat Rut.

Ashkenazim recite Yizkor on this day. One who is davening without a minyan may recite Yizkor as well.

It is customary that those who are in mourning for the loss of a parent do not recite Yizkor during the mourning period (12 months). The Chabad custom is that they remain in Shul during Yizkor but do not recite it (Sefer HaMinhagim Chabad).

The custom of Yizkor is to give tzedaka (after Yomtov) in memory of the departed.

According to Chabad custom, Av HaRachamim should be recited even by those who do not say Yizkor (the Previous Lubavitcher Rebbe).At the close of every Yom Tov, the Lubavitcher Rebbe would lead a farbrengen (inspirational Chassidic gathering) that included singing the songs associated with (or composed by) the Ba’al Shem Tov, the Maggid of Mezritch and all of the Chabad Rebbes. This would serve as a bridge between the holiness of the Yom Tov, and the mundane time of the rest of the year.

The Havdalah of this night  includes a candle or smelling spices as on every Motzei Shabbat.

One should eat an additional dish of food on this day in order to celebrate it as a mini-holiday (Shulchan Aruch HaRav 429:17).

Days of Tashlumin, Sunday, 8 Sivan/May 31– Thursday, 12 Sivan/June 4

The five days that follow the holiday of Shavuot (or six in Israel) are known as yemeitashlumin (days of compensation) as in the Temple era one could bring the holiday sacrifices on these days.

Many communities do not recite Tachnun (supplicatory prayers that follow the morning and afternoon Amidah on most weekdays) during the first 12 days of Sivan (See Mishnah Berurah, 131:36). This is also the Chabad custom ( Siddur HaRav).

Some resume Tachnun on 9 Sivan/June 1 (See Rama, 49: 3), while others do not resume until 14 Sivan (Shabbat, June 6). (In fact, no tachanun is ever said on Shabbat but certain prayers are omitted when Shabbat occurs on days that would otherwise have no tachanun).

One may not fast or deliver eulogies on these days. (See sources cited in Piskei Teshuvot, 494, note 51. See there regarding the fast of a Chattan and Kallah).