Rabbi Yosef Leib Bloch (1860-1930), rav and rosh yeshiva of Telz, bases his discussion of Zionism on the statement of Chazal (Sanhedrin 97a), "The son of Dovid will not come until the Jewish people give up on the redemption... When Rabbi Zeira saw the rabbis occupied with moshiach, he said, "Please do not delay his coming.' For three things come when we take our attention off them - moshiach, a fortuitous find and a scorpion."
The Telzer Rav asks: Thinking about a fortuitous find may not help, but it certainly doesn't hurt. And giving up on finding one doesn't make it any more likely that you will find one. So if moshiach is compared to a fortuitous find, why should thinking about moshiach delay his coming?
Furthermore, how could we be obligated to give up on the redemption? Chavakuk (2:3) says, "If he tarries, wait for him." One of the questions we will be asked on the day of judgment is, "Did you wait for the redemption?" And in each of the three daily prayers, as well as in the blessings after the meal, we mention the kingship of David and the rebuilding of Jerusalem. We say in Kedushah on Shabbos, "Reign over us, for we are waiting for You." Clearly, our waiting is the merit upon which we base our request for Hashem to reign over us. How then could Rabbi Zeira say that we should give up on the redemption?
He answers that Rabbi Zeira means not that we should give up on the redemption, but that we should give up on bringing the redemption through our own efforts. The redemption time has been planned by Hashem since before creation, and we have no way of knowing it. Many Jews throughout history have made the mistake of searching for ways to bring the redemption prematurely - each generation in its own style. In the earlier generations attempts were made to use spiritual methods, such as Kabbalah, and in the later generations attempts were made to use natural means. But all these did not succeed and cannot ever succeed, for the redemption cannot come about through human effort. It can only come when we take our attention off these efforts in the realization that they are futile.
This is the comparison to a fortuitous find: a person has no way of knowing where he will run across such a find. Thinking about it will not hurt, but if he moves in a certain direction to look for it, it is quite likely that he will actually be moving further away from it. In the same way, if we make our own efforts to bring the redemption, not only will these efforts fail, but they are likely to bring us further away from the redemption. By striving for what we think is the redemption, we will be distancing ourselves from the true path of redemption. Whatever redemption we do find will not be the promised redemption; this itself causes the redemption to recede further.
We have witnessed this many times in history: those who sought ways to bring the redemption ended up even further from the truth and the true emunah. And we see this today as well: that because they desired to bring the redemption with their own power, the people of our generation have become distanced from Torah and emunah. This has caused many tragedies, and thanks to them we have taken many steps backward, away from the redemption - may Hashem have mercy.
When Rabbi Zeira saw the rabbis occupied with moshiach, it means they were occupied with finding ways to accelerate the redemption. And we can be sure that these great Amoraim were pursuing holy and exalted methods. Yet Rabbi Zeira told them to stop, because their path would lead them in the opposite direction - away from the redemption. (Shiurei Daas, Volume 1, Chelek 2, Shiur 5 - Dor Haflaga, pp. 270-272)