On Shabbat chol hamoed Sukkot, the haftarah is from the book of Ezekiel. It speaks about the war of Gog and Magog, which will be the prelude to the coming of Moshiach.1 It is followed by Ezekiel's vision of the Third Temple.

In the haftarah, Gog, king of Magog, together with his allies, which is understood to mean the whole world (this is hinted in the numerical value of the words Gog uMagog, which equal 70, the number of nations originally counted in the Torah) will converge on Jerusalem.

The haftarah then describes what G‑d will do to Gog, Magog, his allies, and the lands that support the war. There will be an earthquake, many fires, and much more. The armies that will converge on Israel will be so vast that their weapons will provide fuel for seven years, and it will take seven months to bury all their dead.

After this war, hatred towards the Jewish people will cease, as all their opponents will be gone. It will be the war that will end all wars and everyone will accept G‑d as their master.

Why do we read this haftarah on Shabbat chol hamoed Sukkot?

One connection is its similarity to the Torah reading. On Shabbat chol hamoed Sukkot, we read about the making of the second set of tablets, which signifies G‑d's acceptance of the Jewish people after the sin of the Golden Calf. This can be seen as a new era of greatness and closeness between G‑d and the Jewish people. Our haftarah also speaks of the acceptance of the Jewish people following this dark exile, which was brought on us, as we say in the holiday prayers, “because of our sins.” The difference between then and now is that the acceptance after the Golden Calf was followed by an exile. However, when Moshiach comes, the acceptance will be complete and not to be followed by another exile.

Another connection is that according to many, the war of Gog and Magog will happen during the month of Tishrei. But why read it on Sukkot? Because in the haftarah of the first day of Sukkot, it speaks of the same war and mentions that the gentiles will have to keep the holiday of Sukkot. Another reason is that our haftarah tells about the transformation of the nations of the world, and on Sukkot 70 sacrifices were brought for the 70 nations of the world.

However, I feel that the main reason is that Sukkot is the holiday of the harvest, when we gather all the produce we toiled so hard for. On a spiritual level, we start to gather in the benefits of our efforts throughout the month of Elul, the High Holidays and the Ten Days of Repentance. After the war of Gog and Magog, we will reap the benefits of our toil in this dark exile and we will be forever together with G‑d.

We are left with a question. I understand the connection between the haftarah and Sukkot, but why read it on Shabbat chol hamoed? Why not read it on the first day of Sukkot? The answer is that the message of the haftarah, while being connected to Sukkot, is not an annually recurring theme of the holiday. Since Shabbat chol hamoed doesn't occur every year, for example, when the first day of Sukkot is Shabbat, there is no Shabbat chol hamoed, it is the perfect time to have a message that connects to the holiday but is not recurring.

This haftarah is about the coming of Moshiach, which we don't need to be recurring; we just need it to happen once, with or without a war. May he come soon.