Can you please elaborate on what you wrote: "The prophets & rabbinic sources are unanimous, that once the redemption has begun, it may face challenges, but it will never stop!' Can we be sure that there won't be another exile? After all, over history, there have been several false messiahs!

There's a formidable list of great leaders who unabashedly declared that the modern return to Israel is indeed the beginning of redemption as said in most shuls world-wide, "ברך את מדינת ישראל ראשית צמיחת גאולתנו", including: the Chafetz Chayim, the Netziv, the Malbim, Rav Kook, Rav Shlomo Zalman Auerbach, Rav Tzvi Pesach Frank, & many more. They declared so, despite the fact that they had already seen the catastrophes wrought by the revelation of Shabtai Tzvi & other false messiahs & if they had even the slightest doubt, they would surely have been more cautious. They basically based their decision upon 3 points: a. Revival of Eretz Yisrael: The "קץ המגולה", The Talmud details: "There is no more 'revealed/clear sign' than that which is written, 'And you, mountains of Israel, give forth your branches, & carry forth your fruit, for My Nation of Israel is coming soon'. Rashi explains that when the Land of Israel (barren for so long) will return to produce fruit abundantly, that is the clearest sign that the redemption is underway (Sanhedrin 98a based on Yechezkel 36, 8). b. The Ingathering of the Exiles (קיבוץ גלויות) is the opposite of exile. Gathering & unity instead of scattering & distance. The present 7,181,000 Jews in Israel, the largest Jewish population in the world today & many statisticians claim that already most (!) of world Jewry today lives in Israel, for the first time since the exile of the 10 tribes 2,700 years ago. Not only the number but the "spread" of 1,900,000 olim from East Europe, 494,000 from Central & West Europe, 478,000 from Asia, 514,000 from Africa, & 211,000 from the Americas is also significant. Anyone who doesn’t call the above "ingathering of the exiles" is denying reality! Nevertheless, a skeptic could seemingly say that despite these undeniable facts, especially with the nuclear threat from Iran, who knows what the future holds? However, as we have said above, the certainty is based on the fact that chazal state in many sources that there will not be another exile after the third return to Zion. For example: Midrash Tanchuma, Parshat Shoftim 9; Yalkut Shimoni Zechariya 581: "’and the third will remain in her’ (Zecharia 13, 8), that we will only resettle Israel in the third redemption, the first redemption was from Egypt, the second redemption is that of Ezra (to build the 2nd Temple), the third has no end". Note, the negative language used here, both at the beginning: "will only resettle Israel in the third redemption" & at the end: "has no end", leaves no room for misunderstanding. Nevertheless, the skeptic may still argue: even if we have seen that after the ingathering of exiles there won’t be another exile, how do we know that what is happening today is the ingathering of exiles? In order to complete the picture, we'll refer to another Oral tradition that we received from chazal, that the number that is fixed for the ingathering of the exiles is 600, 000 Jews in Israel. When we arrive at this number it is unreasonable that Hashem will "send them back" to chutz la’aretz just in order to bring them back to Israel. Yalkut Shimoni, Hoshea 518: "It is written ‘and I answered her there like in the days of her youth & like the day that she went up from the land of Egypt’ (Hoshea 2, 17), just as 600, 000 left Egypt & 600, 000 entered the Land of Israel, also in the days of Mashiach it will be with 600, 000." Thank G-d, today 7,181,000 Jews live in Israel, more than 10 times (!) that number. In summary, as soon as there are 600,000 Jews in Israel there will not be another exile. c. The State of Israel- The gmara (Shabbat 151b) and the Rambam (Hil. Tshuva 9, 2 (simplify the issue even more, "There is no difference between today (=the exile) & the days of mashiach except that (then) we will not be subject to the nations of the world ". In other words, we'll have an Independent Jewish State. The role of independence in the process of redemption is not just a philosophic idea, rather it is also well-based with practical halachic ramifications (="nafka mina"). The Shulchan Aruch rules: "one who sees the cities of Judea in their destruction must say: ‘your holy cites have become deserted’, and rip his clothes" as a sign of mourning (Shulchan Aruch, O. Ch. 561, 1). What is the halachic definition of "destruction" which obligates this tearing of one’s clothes? The Mishna Brura (ibid, 2) explains that "even if Jews live there, the cities are considered to be in "destruction", because Arabs rule over them". Clearly, independence is seen as the opposite of ,"חורבן" "destruction", & consequently, with today's independent State of Israel, the halacha is that we no longer need to tear our garments (just some do so regarding the Kotel). As opposed to the cynics who ask, "Do you have a direct link with Heaven that you know what is going to happen?", the answer is, yes, we do have a direct connection with Heaven, namely the prophets & chazal, & in this case we do know what will not be. There will not be another destruction of the Jewish settlement in Israel. If this is definite enough for the Chafetz Chayim, Rav Kook, Rav Tzvi Pesach Frank, the Sridei Eish, Rav Shlomo Zalman Auerbach & many other aforementioned giants, then yes, it is enough for the rest of us. No false messiah ever revived the deserted Israel, gathered and returned most of the exiles to Israel, nor had a strong formidable Jewish State, which as we saw, are the 3 clearest signs of redemption. Similarly, just as Rav Kook, Rav Herzog & others felt the need in their generation to repeat this guarantee & to emphasize that it is possible to "bank" on it & even to act accordingly, it is also important to do so today. At this time of national trouble, it is particularly important to strengthen the morale of the people, to look at the events with a wise eye - realistic & believing at the same time - & not with a pessimistic & unbelieving eye. These words of chazal were meant precisely for our generation , & we would be wrong to ignore them. As the prophet says: "And I will return the exiled of my people Israel, & they will rebuild & settle desolate cities, & they will plant vineyards & drink their wine, plant gardens & eat their fruit. And I will plant them on their Land, & they will not be removed again from the Land that I have given to them, says Hashem your G-d (Amos, 9:15-16)." Similarly, Yeshayahu prophesizes in this context of redemption (66:9): "Will I begin labor & not give birth?!’ says Hashem. Rashi explains: "Will I bring the woman to the birth-stool & not open her womb to take out the fetus?! In other words, would I start something (the redemption) & not be able to complete it?! Am I not the one who enables all births & now I have stopped myself?!" For more details & sources, see my article: https://www.yeshiva.co/midrash/10933