Old Testament readings use the Septuagint , the Scripture the apostles quoted. Masoretic numbering shown for reference.Learn why

pentecost

noun
A solemn festival of the Jews, so called because celebrated on the fiftieth day after the sixteenth of Nisan, which was the second day of the passover. It was called the feast of weeks, because it was celebrated seven weeks after the passover. It was instituted to oblige the people to repair to the temple of the Lord, there to acknowledge his absolute dominion over the country, and offer him the first fruits of their harvest; also that they might call to mind and give thanks to God for the law which he had given them at Sinai on the fiftieth day from their departure from lEgypt.

pentecost

Whitsuntide, a solemn feast of the church, held in commemoration of the descent of the Holy Spirit on the apostles. Acts 2:1.