Pentecost means "fifty" and designates the fiftieth day after Passover. Pentecost relates to the Old Testament Feast of Weeks. Deut. 16:9-10 reads, "You shall count seven weeks for yourself; you shall begin to count seven weeks from the time you begin to put the sickle to the standing grain. 10 Then you shall celebrate the Feast of Weeks to the Lord your God with a tribute of a freewill offering of your hand, which you shall give just as the Lord your God blesses you." The Feast of Weeks was a religious holiday that occurred at the beginning of the wheat harvest and was a display of thanksgiving to the Lord for His provision.
Pentecost is observed only for two days, and it marks the closing of the Passover season. It has strong agricultural significance since it is associated with the Old Testament context time that mentions the end of the barley harvest and the beginning of the wheat harvest. Historically, Pentecost (Feast of Weeks) became increasingly known for its historical significance associated with the time of the giving of the Law of Moses.