This pasuk caps it off. If there were not enough curses (98) to punish us, we are informed that, just because the curse did not appear in the Torah, we will not be exempted from it. Every illness or blow, in other words, everything that could possibly be imagined – is included in the punishments available for disciplining us, if necessary. This presents us with a very bleak outlook. Horav Mordechai Pogremonsky, zl, addressed this issue, when the Telshe students who were displaced from their yeshivah were living in Shidlov, at the beginning of World War II. Tensions were rising, as fear of the Nazi invasion was becoming more imminent with each passing day.
Rav Pogremonsky distinguished between the makkos ha’kesubos baTorah, those blows that are written in the Torah, and those which are not. Those blows which are not included in the Torah are of a unique nature in that they address the very existence of the Jewish People. These makkos are of a nature that, Heaven forbid, they could destroy our People. It is specifically with regard to this aspect that these blows are ineffective. Hashem has given us a promise that He will never destroy Am Yisrael, our nation – regardless of our iniquity. Chitzai achaleh bahem, “My arrows shall I use up against them (Devarim 32:23): Chazal (Sifri) consider this a blessing in disguise, chitzai kalim v’heim einan kalim, “My arrows will be used up, but they will not be used up.” Klal Yisrael will never cease to exist. This is Hashem’s word.
Therefore, those kelalos, curses/blows that are not in the Torah are of concern, but they should not create anxiety to the point that we think an end, Heaven forbid, will come to our People. That will never happen. Rav Pogremonsky concluded that, while it is true we were witness to brutality and terror that is beyond anything that has ever occurred and beyond anything alluded to in the Torah, it does not mean that we have met our downfall: “Does this mean that we have reached the point of no return? No! If the Nazis come at us with a blow that is not written in the Torah, then it is a clear indication of their defeat. Indeed, the beginning and end of their downfall will be due to their utter brutality towards the Jewish People.”