'Feast of Weeks' in the Bible

"You shall observe the feast of weeks with the first fruits of wheat harvest, and the feast of harvest at the year's end.

You shall keep the feast of weeks to Yahweh your God with a tribute of a freewill offering of your hand, which you shall give, according as Yahweh your God blesses you:

Three times in a year shall all your males appear before Yahweh your God in the place which he shall choose: in the feast of unleavened bread, and in the feast of weeks, and in the feast of tents; and they shall not appear before Yahweh empty:

even as the duty of every day required, offering according to the commandment of Moses, on the Sabbaths, and on the new moons, and on the set feasts, three times in the year, [even] in the feast of unleavened bread, and in the feast of weeks, and in the feast of tents.