הלכה על נדרים 42:6

And so [too,] that which they, may their memory be blessed, said (Nedarim 2b), that there are four vows which are annulled - meaning to say they are completely annulled, such that we do not require a question to a sage [in order to annul it], and like the opinion of Shmuel in the chapter [entitled] Arbaah Nedarim (Nedarim 21b), as the law is according to him. And these are them: vows of exhortation; vows of exaggeration (nonsense); vows of mistake; and vows of duress. And there in the same chapter, [the makeup of] each and every one is clarified. And we have the textual variant in the Talmud Yerushalmi Nedarim 3:1 concerning vows of exhortation, "Rabbi Zeira said, 'That which you say, is when they were not holding up their words, but if they were holding up their words, they would require dispensation'"; meaning to say, if they were holding up their words - meaning that they did not vow as a vow to exhort, but rather they vowed it with precision - they would require a question to a sage. And the same is certainly true of the other three [vows] that are learned in the Mishnah, that if they were holding up their words, they would require a question of a sage. And nonetheless a sage can annul in any situation, so long as he finds an opening to annul [it], meaning to say that he finds some matter that the vower would say, "If I had known this thing at the time of the vow, I would not have vowed."