מילי דחסידותא is the same idea as זה הדבר words bring the greatest holiness down!
There are four types of Jews: רשע who corresponds with ‘עשי, the בינוני who corresponds to יצירה, then the צדיק who corresponds to בריאה, but even he is subject to imperfection (particularly as the word צדיק is used in the ‘borrowed’ way).
Then there is חסיד, who corresponds with אצילות.
נדרים are against אצילות and raise the person to the level of חסיד on two levels,
First by not partaking of material things to be holy by disassociation,
Second by being מתיר or the father is מפר (!!) the vow and the material is used to raise up to holiness. MP3
