והיה ביום ההוא יתקע בשופר גדול ... (ישעי' כז-יג)
Mentioning the many hardships endured by Yaakov Avinu and his family during their long journey to Egypt, Yeshaya HaNavi prophecies that Hashem will ultimately bring Moshiach and end the bitter exile. Interestingly, Yeshaya notes that Hashem will build “a special ‘tower’ - stone by stone in Tzion” (Yeshaya 28:16), but when redeeming Klal Yisroel and rebuilding the Bais Hamikdash, Hashem seems to give no comfort to the nation by making it take so long.
R’ Hillel Rivlin zt”l of Shklov, explains from his Rebbi, the Vilna Gaon zt”l, that even though we may not know the time of the ultimate redemption, it is still supremely important for us to know beforehand that the beginning of the redemption will come gradually, slowly, little by little. He explains that the Torah tells us, “I will direct it at my slow pace” (Bereishis 33:14) - a reference to the times of redemption. But obviously Hashem can bring Moshiach in a more expeditious fashion if He so chooses. Nevertheless, the Almighty intends to do it slower because if the redemption came too quickly, and along with it a harsh measure of Middas HaDin as Chazal have forewarned, then Jews who are not so righteous and do not have the merit to be redeemed, will be unable to bear the suffering.
Therefore, in His infinite kindness, Hashem arranged that the future redemption of Klal Yisroel will arrive gradually, not all at once, thereby giving all Jews a chance with ample time to repent and return to Him fully.