Exodus 34:22

And the festival of weeks, shalt thou make to thee, the firstfruits of the wheat harvest, - and the festival of ingathering, at the closing in of the year:

Exodus 23:16

And the festival of harvest with the firstfruits of thy labours, which thou shalt sow in the field, And the festival of ingathering - at the outgoing of the year, when thou hast gathered in thy labours out of the field.

Numbers 28:16-31

And, on the first month on the fourteenth day of the month, shall be a passover unto Yahweh;

Numbers 29:12-39

And on the fifteenth day of the seventh month, a holy convocation shall there be unto you, no laborious work, shall ye do, but ye shall celebrate a festival unto Yahweh, seven days.

Deuteronomy 16:10-15

So shalt thou keep the festival of weeks unto Yahweh thy God, in the measure of the freewill offering of thy hand which thou shalt give, - as Yahweh thy God shall bless thee.

John 7:2

But the feast of the Jews was near, that of the pitching of tents.

Acts 2:1

And, when the day of pentecost was filling up the number of days they were all together with one intent; -

Treasury of Scripture Knowledge

Summary

And thou shalt observe the feast of weeks, of the firstfruits of wheat harvest, and the feast of ingathering at the year's end.

Bible References

Feast of weeks

Exodus 23:16
And the festival of harvest with the firstfruits of thy labours, which thou shalt sow in the field, And the festival of ingathering - at the outgoing of the year, when thou hast gathered in thy labours out of the field.
Numbers 28:16
And, on the first month on the fourteenth day of the month, shall be a passover unto Yahweh;
Numbers 29:12
And on the fifteenth day of the seventh month, a holy convocation shall there be unto you, no laborious work, shall ye do, but ye shall celebrate a festival unto Yahweh, seven days.
Deuteronomy 16:10
So shalt thou keep the festival of weeks unto Yahweh thy God, in the measure of the freewill offering of thy hand which thou shalt give, - as Yahweh thy God shall bless thee.
John 7:2
But the feast of the Jews was near, that of the pitching of tents.
Acts 2:1
And, when the day of pentecost was filling up the number of days they were all together with one intent; -

General references

Exodus 23:14
Three times, shalt thou keep festival to me, in the year.
Leviticus 23:15
Then shall ye keep count to yourselves from the morrow of the sabbath, from the day ye brought in the wave sheaf, - seven sabbaths complete, shall there be:
Deuteronomy 16:9
Seven weeks, shalt thou count unto thee, - from the beginning of thrusting in the sickle into the standing corn, shalt thou begin to count, seven weeks.