The Festival of Shavuot was established as the wheat harvest festival. Each person was commanded to bring to the Lord in the Temple two loaves and the first fruits of his produce from the Seven Species ,with which the Land of Israel is blessed. After the destruction of the Temple, the Jewish people were unable to bring the bread of the land to the holy place. Once the Jews returned to the Land of Israel, the tradition was renewed. Every year, hundreds of people stream on foot from throughout Jerusalem to arrive at the Kotel (Western Wall) early Shavuot morning in order to pray at a sunrise service service in front of the Wall .
According to legend, when the Torah was given on Mount Sinai, the barren desert exploded with blooming flowers, as if the earth itself rejoiced. This, along with the fact that Shavout began as an agricultural festival, makes it customary to embellish the synagogues and houses with greenery and with branches of trees, roses and other flowers, and spices. It is the practice of some to stand trees next to the Torah ark and the Reader's lectern. School children wear wreaths and even decorate their houses with leaves and flowers.
It is customary to read The Book of Ruth on Shavuot. The act of Ruth's conversion took place during the harvest season, from the beginning of the barley harvest to the conclusion of the wheat harvest. Traditionally, Shavuot is the day that King David was born, and died. The Book of Ruth establishes David's pedigree of David, who was the eventual product of the union between Ruth and Boaz. David is the beginning of the line of kings in Israel leading to the Messiah. The outcome of Boaz and Ruth's union attests to their personal greatness as well as the magnitude of the reward for deeds of kindness and the degree of recognition owed to a righteous convert.
It is customary to eat dairy products for breakfast on the holiday, as well as honey or honey cakes. Several reasons can be sited due to which this custom came into practice. Firstly, Torah is compared to honey and milk. Secondly, The word for milk, halav, has the numerical value of 40, corresponding to the 40 days Moses spent on Mount Sinai studying the Torah which he then taught to the Israelites in the wilderness. The acronym formed from the Hebrew of "To declare Your lovingkindness in the morning" (Psalms 92:3) is halav, and the entire Torah is lovingkindness. Thirdly, Moses was born on the seventh day of the Hebrew month of Adar, hidden by his mother, Jochebed for three months and found by Pharoah's daughter in the Nile bulrushes on 6th Sivan, the future date of Shavuot. According to legend, the baby Moses refused milk from his new non-Jewish mother, and his sister Miriam arranged for his natural mother to nurse him. Eating dairy products reminds us of this past history. Fourthly, twice in the Bible (Exodus 23:19; 34:26), a reference is made to bringing the first fruits "You shall bring the first-fruits of your land to the house of the Lord your God...", juxtaposed with a reference to what rabbis inferred as a command to separate milk from meat "You shall not cook a kid in its mother's milk". Eating dairy food on the Festival of the First Fruits was drawn from this association of ideas. Finally, milk is symbolic of the infancy of the Jewish people, and their birth as a nation at Mount Sinai.
It is customary to remain awake the entire night of Shavuot and to engage in Torah study. The Shavuot night Tikkun (order of study), which includes all portions of the Torah, is studied.
Perhaps inspired by Ruth's choice to embrace the Jewish people, people often complete their learning, go to mikveh, and enter the covenant before Shavuot. Women often take Ruth as their name, replacing their Hebrew name. Jews by choice in many places are called to the Torah for the first time on Shavuot.