הלכה על נדרים 3:7

From the laws of the commandment are that which they, may their memory be blessed, said (Nedarim 2a), "All substitutes for [the expression for] vows are like vows, [substitutes for] dedications are like dedications, [substitutes for] oaths are like oaths, and [substitutes for] nazirite vows are like nazirite vows." [This is such that] (Nedarim 10a), "one who says [that a certain object is] konam, konach or konas, behold, these are substitutes for sacrifice (korban); cherek, cherekh or cheref, behold, these are substitutes for dedication (cherem) [to the Temple treasury]; nazik, naziach or paziach, behold, these are substitutes for naziriteness (nazir); shevutah, shekukah or [if] he vows with [the term,] mohi, behold, these are substitutes for oath (shevuah)." And the reason for the matter of these expressions that the Sages said are judged as if a man brought them out of his lips with the proper expression and [that] we do not concern ourselves to require that his mouth and heart be the same - as behold, he did not bring the proper expression from his mouth - is because these expressions imply the matter. Since anyone who hears would decide about it that this is the intention of the one making an oath or vowing. And since it is like this, behold, it is as if he said the thing clearly and properly. As if you don't say like this, it comes out that there would never be vows or oaths from those with speech impediments (see Mishneh Torah, Laws of Vows 1:16). And in truth, this is not [the case].