The Sefas Emes and Noam Elimelech teach us that the word neder, vow is related to the word dira, dwelling. What does an oath have to do with a dwelling?
Reb Chaim from Divrei Chaim cites the Shem m’Shmuel who questions the entire essence of nedarim: How is it that a person has the power through his verbal declaration to create prohibitions (in the case of nidrei bituei) and create a status of hekdesh (nidrei hekdesh)? This power goes so far that the Gemora is uncertain whether the object of a neder is subject to the laws of me’ilah for violating a neder!
He suggests the following: In essence no new kedushah is being created. The concept of neder is a recognition that beyond what meets the eye, there is a level of kedushah already inherent in the reality around us - the Shechinah already dwells immanently in the world.
Sefas Emes notes that the first person in the Torah to take a neder is Yaakov Avinu. While the other Avos revealed Hashem’s presence as similar to a mountain or a field, Chazal tell us that Yaakov revealed Hashem’s presence as the bayis, a dwelling. Chazal tell us that taking a neder is like building a bamah, an altar used outside the Mikdash. Hashem metaphorically “dwells” in the Bais haMikdash – to create a sanctified space for him - outside those confines is a task fraught with challenge.