Deuteronomy Chapter 16

Deuteronomy 16
 
9-12. The day of Pentecost was evidently thus—whatever day the first handful could be had, it was offered on the day after the Sabbath (Sunday); thence to the seventh Sabbath was forty-nine, and then on the fiftieth (Sunday) Pentecost was celebrated. In itself it had no connection with the previous feast of unleavened bread—historically it was so, but they were distinct ordinances. See also Lev. 23:15, 16.