No War of Gog and Magog (Shem MiShmuel)

See that it is explained in the writings that after the ingathering of the Exiles of the future will be the war of Gog and Magog. But it is a received tradition in our hands from our holy Rebbeim, their souls be in Eden, that now that the exile was so long, we have been absolved of the war of Gog and Magog, and after the ingathering of the exiles Yisrael will sit in peace on their land forever, like it was in Egypt that the difficulty of the servitude fulfilled [the required] 400 years [of servitude in far fewer years], so too this exile in the opposite manner: that the long length of time [of this last exile] has fulfilled the difficulty of servitude and the many evils and travails that we endured will in the future come upon the haters of Israel. And don't be astonished that this appears to be a change from what is written explicitly in the Torah, for we see that in Egypt the verse explicitly states 400 years and nonetheless the difficulty of the servitude fulfilled and reduced them by 190 years. So, too, as regards the matter of the war of Gog and Magog.

Shem MiShmuel, parshas Vayigash 5677, p. 298