Observed on the 15th day of the 7th month of the Israelite calendar.
Leviticus 23:
33- And the LORD spake unto Moses, saying,
34– Speak unto the children of Israel, saying, The fifteenth day of this seventh month shall be the feast of tabernacles for seven days unto the LORD.
35– On the first day shall be an holy convocation: ye shall do no servile work therein.
36– Seven days ye shall offer an offering made by fire unto the LORD: on the eighth day shall be an holy convocation unto you; and ye shall offer an offering made by fire unto the LORD: it is a solemn assembly; and ye shall do no servile work therein.
37– These are the feasts of the LORD, which ye shall proclaim to be holy convocations, to offer an offering made by fire unto the LORD, a burnt offering, and a meat offering, a sacrifice, and drink offerings, everything upon his day:
38– Beside the sabbaths of the LORD, and beside your gifts, and beside all your vows, and beside all your freewill offerings, which ye give unto the LORD.”
39– Also in the fifteenth day of the seventh month, when ye have gathered in the fruit of the land, ye shall keep a feast unto the LORD seven days: on the first day shall be a sabbath, and on the eighth day shall be a sabbath.
40– And ye shall take you on the first day the boughs of goodly trees, branches of palm trees, and the boughs of thick trees, and willows of the brook; and ye shall rejoice before the LORD your God seven days.
41–And ye shall keep it a feast unto the LORD seven days in the year. It shall be a statute forever in your generations: ye shall celebrate it in the seventh month.
42– Ye shall dwell in booths seven days; all that are Israelites born shall dwell in booths:
43– That your generations may know that I made the children of Israel to dwell in booths, when I brought them out of the land of Egypt: I am the LORD your God.
44– And Moses declared unto the children of Israel the feasts of the LORD.
According the Holy Scriptures all nations at one time or another came and fought against the children of Israel. The nations that remain after Armageddon shall indeed rejoice in the new Kingdom of Heaven on earth. They shall obey the Lord’s commandments and honor the children of Israel. That explains why the disciples asked Christ this question
Acts 1:
6–When they therefore were come together, they asked of him, saying, Lord, wilt thou at this time restore again the kingdom to Israel?
Acts 1:
7– And he said unto them, it is not for you to know the times or the seasons, which the Father hath put in his own power.
The disciples were well aware of the prophecies regarding Israel ruling the Kingdom of Heaven under Christ.
Daniel 2:
44– And in the days of these kings shall the God of heaven set up a kingdom, which shall never be destroyed: and the kingdom shall not be left to other people, but it shall break in pieces and consume all these kingdoms, and it shall stand forever.
Daniel 7:
27- And the kingdom and dominion, and the greatness of the kingdom under the whole heaven, shall be given to the people of the saints of the most High, whose kingdom is an everlasting kingdom, and all dominions shall serve and obey him.
Daniel 7:
28– Hitherto is the end of the matter.
That is the end of the matter meaning the divine plan of the Most High, to give everything under the whole heaven to the children of Israel that repent in Christ.
All nations shall keep the Lord’s commandments including His high holy days, remembering and honoring what the Lord did for the children of Israel.
The holy scriptures explain that in detail regarding the Feast of Tabernacles.
Zechariah 14:
16– And it shall come to pass, that every one that is left of all the nations which came against Jerusalem shall even go up from year to year to worship the King, the LORD of hosts, and to keep the feast of tabernacles.
17– And it shall be, that whoso will not come up of all the families of the earth unto Jerusalem to worship the King, the LORD of hosts, even upon them shall be no rain.
18– And if the family of Egypt go not up, and come not, that have no rain; there shall be the plague, wherewith the LORD will smite the heathen that come not up to keep the feast of tabernacles.
19– This shall be the punishment of Egypt, and the punishment of all nations that come not up to keep the feast of tabernacles.
20– In that day shall there be upon the bells of the horses, HOLINESS UNTO THE LORD; and the pots in the LORD’s house shall be like the bowl’s before the altar.
21– Yea, every pot in Jerusalem and in Judah shall be holiness unto the LORD of hosts: and all they that sacrifice shall come and take of them, and seethe therein: and in that day there shall be no more the Canaanite in the house of the LORD of hosts.
In the past during the time of Joshua and the Judges of Israel there remained many Canaanites in the land but in the Kingdom, there shall be none. Neither shall any Israelite learn the customs of the Canaanites to pollute the land anymore.