Exodus 34:22

And thou shalt observe the feast of weeks, of the first-fruits of wheat-harvest, and the feast of in-gathering at the year's end.

Exodus 23:16

And the feast of harvest, the first-fruits of thy labors, which thou hast sown in the field: and the feast of in-gathering, which is in the end of the year, when thou hast gathered in thy labors out of the field.

Numbers 28:16-31

And on the fourteenth day of the first month is the passover of the LORD.

Numbers 29:12-39

And on the fifteenth day of the seventh month ye shall have a holy convocation; ye shall do no servile work, and ye shall keep a feast to the LORD seven days:

Deuteronomy 16:10-15

And thou shalt keep the feast of weeks to the LORD thy God with a tribute of a free-will-offering of thy hand, which thou shalt give to the LORD thy God, according as the LORD thy God hath blessed thee:

John 7:2

Now the Jews' feast of tabernacles was at hand.

Acts 2:1

And when the day of Pentecost was fully come, they were all with one accord in one place.

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 feast of harvest, the first-fruits of thy labors, which thou hast sown in the field: and the feast of in-gathering, which is in the end of the year, when thou hast gathered in thy labors out of the field.
Numbers 28:16
And on the fourteenth day of the first month is the passover of the LORD.
Numbers 29:12
And on the fifteenth day of the seventh month ye shall have a holy convocation; ye shall do no servile work, and ye shall keep a feast to the LORD seven days:
Deuteronomy 16:10
And thou shalt keep the feast of weeks to the LORD thy God with a tribute of a free-will-offering of thy hand, which thou shalt give to the LORD thy God, according as the LORD thy God hath blessed thee:
John 7:2
Now the Jews' feast of tabernacles was at hand.
Acts 2:1
And when the day of Pentecost was fully come, they were all with one accord in one place.

General references

Exodus 23:14
Three times thou shalt keep a feast to me in the year.
Leviticus 23:15
And ye shall count to you from the morrow after the sabbath, from the day that ye brought the sheaf of the wave-offering; seven sabbaths shall be complete:
Deuteronomy 16:9
Seven weeks shalt thou number to thee: begin to number the seven weeks from the time when thou beginnest to put the sickle to the corn.