There is a well-known story told about a great person who promised that when he passes away, he will continue to storm the heavens that Hashem must bring the Geuah! As time has passed and Moshiach had not come, another great person said – concerning the first ‘Gadol’ – that seemingly when he ascended the heavens they treated him to such high revelations, which caused him to “forget” his promise. The 2nd ‘Gadol’ assured everyone that he would not allow himself to be bribed…However, as we can see, Moshiach still isn’t here. It seems he too was ‘bought’ off…

There seems to be only one solution, that one can make to ascertain that he will not be bribed into silence! that is: to make a Neder (Vow) based on the Authoritative understanding of the public, of which the Halacha is that it cannot be annulled. (see Gittin 36) Thereby obligating the heavenly courts to allow the person to keep his vow.
… This leads us to be reassured that very soon Moshiach will be revealed speedily in our time.