The second high holy day of the Jews is the one which Moses called Chag Shebhúos, the Feast of Weeks. This is because they had to count seven weeks, which makes forty-nine days, from Passover, and then the fiftieth day was the Feast of Pentecost, about which Moses writes thus Deut. 16.10; Lev. 23.15: Seven weeks shall you count, and begin to count from the time that you put the sickle to the standing corn, and you shall hold the festival of weeks to the Lord your God, contributing a freewill gift of your hand, according as the Lord has blessed you. And you shall be happy before God your Lord etc. It is also called the Harvest Festival, because the harvest began then. Also, the Festival of Firstlings, because they offered up the firstlings of the new fruits of the harvest in thanksgiving as may be seen in the fourth book of Moses. It was also called Pentecost in the New Testament, as you can read in the Acts of the Apostles and elsewhere. Acts 2.1; Acts 20.16; I Cor. 16.8.
First of all, they have a very precise way of reckoning. They begin to count on the second night of Passover, when the stars come out, with this little prayer: Blessed are you, Lord our God, king of the world, who has sanctified us with his commandments, and commanded us to count the Omer, (that is, the days of the harvest) and today is the first day. Thus they continue all the days, until the seventh day, when they say after the prayer: And today is seven days, which make one week. On the eighth day they say: And today is eight days, which make one week and one day. They count thus further all the days and all the weeks, until the forty-ninth day, which is the eve of Pentecost. This reckoning must be done in a standing position, as the Rabbis decreed. And since they cannot fulfil the feast as it is written in the Law, they pray every day that God will return to them the city of Jerusalem, and build the Temple, so that they may observe the feast with all the offerings, as the Law requires. They also write that God commanded them to count to the feast of Weeks or the harvest, because when they were still on their own land, there would be many crows in their fields, and everyone would be involved in the harvest, and they could easily forget about the feast, with the result that they would not go up to Jerusalem and offer to God the firstlings as he had commanded them. They write too that it may be compared to a king who comes into a city where a count or great lord lies in prison. He begs the king to release him, and the king answers: After so and so many weeks you will be free and at liberty, and I shall give you my daughter as your wife. So then the prisoner begins to count the days and the weeks and the hours until the day comes which the king has designated for him. In the same way did God act towards the Israelites. When they were still in Egypt, he told them: With an outstretched arm I shall lead you out of Egypt. You will count seven weeks after Passover, and then I shall give you also my daughter the Thorah, the holy law, to wife. (The Jews soon fell away from this bride, as Moses and the other prophets declared about them.)
Women are not required to count these days, since it is a commandment which is tied annually to a specific time, from which women are exempt.
No one may be bled on the eve of Pentecost, for they write in the Talmud and in their Minhagim that on this night a very dangerous and bad wind or breeze blows,which is called Tabhoach, destroyer or oppressor, which the people of Israel would have brought about if they had not willingly and gracefully accepted the law which was offered to them on the following day.
Pentecost is celebrated for two days on account of Saphek [doubt] as is done with Passover. They do not have numerous ceremonies apart from the offerings mentioned in the book of the Law which they take out on each day, they call up five men who read about the offerings of the day which were offered formerly.
In memory of the law, they spread grass in their houses, on the streets and in their shuls, and they place greenery in the windows, just as it was around Mount Sinai, which was green when they received the law.
Also, they eat many milk meals, pancakes and such things made with milk, because the law which they received on this day is white, pure, and sweet like milk. They make a kind of flat cake which is high and thick in seven layers, and they call it Sinai cakes in remembrance of the seven heavens through which God journeyed from Mount Sinai. They also take good wine and meat, because they hold Ki en Simchah belo basar, there is no joy without meat. It is written concerning this feast that you should be happy before God your Lord, you and your son and your daughter.
What did the prophets say about these pious Jews who took the Law to wife?