The Feast of Tabernacles is a seven-day feast starting on the fifteenth day of the seventh month.  Even though the Feast is seven days long, rather confusingly perhaps, the Bible refers to the eighth day of it.

Lev 23:34  “Speak to the children of Israel, saying: ‘The fifteenth day of this seventh month shall be the Feast of Tabernacles for seven days to the LORD.
Lev 23:35  On the first day there shall be a holy convocation. You shall do no customary work on it.
Lev 23:36  For seven days you shall offer an offering made by fire to the LORD. On the eighth day you shall have a holy convocation, and you shall offer an offering made by fire to the LORD. It is a sacred assembly, and you shall do no customary work on it.

The eighth day is a day of rest where no customary work is done.  This instruction is repeated a few verses later.

Lev 23:39  ‘Also on the fifteenth day of the seventh month, when you have gathered in the fruit of the land, you shall keep the feast of the LORD for seven days; on the first day there shall be a sabbath-rest, and on the eighth day a sabbath-rest.

The eighth day of the Feast of Tabernacles is also mentioned in Numbers.

Num 29:12  ‘On the fifteenth day of the seventh month you shall have a holy convocation. You shall do no customary work, and you shall keep a feast to the LORD seven days.

Num 29:35  ‘On the eighth day you shall have a sacred assembly. You shall do no customary work.

As a point of interest, Jesus Christ also went up (to Jerusalem) to the Feast of Tabernacles.

Joh 7:2  Now the Jews’ Feast of Tabernacles was at hand.

Joh 7:10  But when His brothers had gone up, then He also went up to the feast, not openly, but as it were in secret.

On the last day, the great day of the feast, Jesus stood and spoke to the crowds.

Joh 7:37  On the last day, that great day of the feast, Jesus stood and cried out …

Was this last day the eighth day or the seventh day?  It was almost certainly the eighth day when you consider what Jesus spoke about and its meaning, which we will look at later.

What then is the meaning of the eighth day of the Feast of Tabernacles?  Its meaning is revealed through the harvest seasons and what they symbolise.

In ancient Israel there were three harvests, two in the spring (barley and wheat), and the third in late summer stretching into early autumn.  These three harvests correspond to three feast seasons: the Feast of Unleavened Bread, the Feast of Weeks, and the Feast of Tabernacles.

Exo 23:14  “Three times you shall keep a feast to Me in the year:
Exo 23:15  You shall keep the Feast of Unleavened Bread (you shall eat unleavened bread seven days, as I commanded you, at the time appointed in the month of Abib, for in it you came out of Egypt; none shall appear before Me empty);
Exo 23:16  and the Feast of Harvest, the firstfruits of your labors which you have sown in the field; and the Feast of Ingathering at the end of the year, when you have gathered in the fruit of your labors from the field.
Exo 23:17  “Three times in the year all your males shall appear before the Lord GOD.

Deu 16:16  “Three times a year all your males shall appear before the LORD your God in the place which He chooses: at the Feast of Unleavened Bread, at the Feast of Weeks, and at the Feast of Tabernacles; and they shall not appear before the LORD empty-handed.

More detail of these three Feast seasons can be found in Leviticus 23. 

In the Bible, particularly in the New Testament, grain harvests symbolise a “harvesting” of souls to eternal life.  For example:

Mat 9:37  Then He said to His disciples, “The harvest truly is plentiful, but the laborers are few.

Joh 12:24  Most assuredly, I say to you, unless a grain of wheat [Jesus Christ] falls into the ground and dies, it remains alone; but if it [Jesus Christ] dies, it produces much grain [resurrected saints].

The parable of the Sower, Matthew 13:1-9.

The parable of the Weeds, Matthew 13:24-30.

Putting the pieces of the puzzle together we see that the three Feast seasons symbolise three “harvests” of souls.

The Feast of Unleavened Bread:  the first harvest of souls – the resurrection of Jesus Christ

The Feast of Unleavened Bread contains the wave sheaf offering which pictures the resurrected Jesus Christ.  (See “What is the meaning of the wave sheaf offering?”) 

The Feast of Pentecost: the second harvest of souls – the resurrection of the saints (God’s people)

The Feast of Pentecost pictures the resurrection of the saints (God’s people).  (See “What is the meaning of the Pentecost?”) 

The Feast of Tabernacles: the second harvest of souls – the resurrection of the rest of the dead

The Feast of Tabernacles pictures the one-thousand-year reign of Jesus Christ.  (See “What is the meaning of the Feast of Tabernacles?”)

Rev 20:4  And I saw thrones, and they sat on them, and judgment was committed to them. Then I saw the souls of those who had been beheaded for their witness to Jesus and for the word of God, who had not worshiped the beast or his image, and had not received his mark on their foreheads or on their hands. And they lived and reigned with Christ for a thousand years.

At the end of the feast is the eighth day.  This pictures the resurrection of the rest of the dead. 

Rev 20:5  But the rest of the dead did not live again until the thousand years were finished. This is the first resurrection.
Rev 20:6  Blessed and holy is he who has part in the first resurrection. Over such the second death has no power, but they shall be priests of God and of Christ, and shall reign with Him a thousand years.

The first resurrection mentioned in verses 5 and 6 refers to those who live and reign with Christ for a thousand years, not to the “rest of the dead”.  The rest of the dead is the vast majority of humanity.  They are resurrected to a physical life and offered salvation.  This is what the eighth day pictures.  The eighth day of the Feast of Tabernacles pictures the time after the one-thousand-year reign of Jesus Christ when the rest of the dead (those who have not received salvation) are resurrected to a physical life and offered salvation.

Let’s return to John 7:37-39 and have a look at what Jesus spoke about on “the last day, that great day of the feast”.

Joh 7:37  On the last day, that great day of the feast, Jesus stood and cried out, saying, “If anyone thirsts, let him come to Me and drink.
Joh 7:38  He who believes in Me, as the Scripture has said, out of his heart will flow rivers of living water.”
Joh 7:39  But this He spoke concerning the Spirit, whom those believing in Him would receive; for the Holy Spirit was not yet given, because Jesus was not yet glorified.

Jesus spoke about anyone who wants being able to receive the Holy Spirit.  The Holy Spirit is necessary for salvation.  So Jesus was speaking about salvation being offered to everyone.  This fits with the meaning of the eighth day, which makes it very probably Jesus Christ spoke about this on the eighth day.

Conclusion

The eighth day of the Feast of Tabernacles pictures the time after the one-thousand-year reign of Jesus Christ when the rest of the dead (those who have not received salvation) are resurrected to a physical life and offered salvation.