Nazir, Chapter 4, Mishnah 3. The Mishnah deals with a woman who took a vow of nezirus and then violated the laws of nezirus, and it distinguishes between a case where her vow is still in force and a case where her husband annulled her vow without her knowing it.
The first clause - she vowed to be a nezirah and violated her nezirus:
"Ha'ishah shenadrah venazir" - a woman who took a vow of nezirus is a nezirah in every respect. "Vehaysah shosah beyayin umitamah lemeisim" - and she violates her nezirus by drinking wine or by becoming tamei through contact with the dead, which are among the violations of the laws of nezirus. "Harei zu sofeges es ha'arba'im" - she receives lashes, because she transgressed a lo saaseh, a negative prohibition of the Torah for which one is liable to lashes.
Her husband annulled the vow and she did not know:
"Heifer lah ba'alah vehi lo yad'ah shehefer lah ba'alah" - the husband annulled the vow of nezirus, and the woman does not know about it. "Vehaysah shosah beyayin umitamah lemeisim" - meanwhile, thinking that she is still a nezirah, she violates the nezirus, as far as she knows, by drinking wine or by becoming tamei through contact with the dead. "Einah sofeges es ha'arba'im" - she does not receive lashes. Even though she believes she has sinned, the reality is that her husband annulled the vow and she is no longer a nezirah, and therefore she transgressed no prohibition. This is the view of the first Tanna.
The view of Rabbi Yehudah:
"Rabbi Yehudah omer: im einah sofeges es ha'arba'im - tispog makas mardus" - true, she does not receive the forty lashes, for those are given for transgressing a Torah prohibition, and she did not actually transgress one; but at the very least she should receive makas mardus. Makas mardus is a form of lashes given for transgressing a rabbinic law. In this case there is not even a rabbinic law that was actually transgressed, but rather the very fact that she thought she was committing a transgression, and even though she did not really transgress, someone who performed an act of rebellion of this sort against the Torah is given, in Rabbi Yehudah's view, the lashes that are of rabbinic origin.
In summary: in this Mishnah we learned that a woman who took a vow of nezirus and violated her nezirus by drinking wine or by becoming tamei through contact with the dead receives forty lashes; but if her husband annulled the vow and she did not know about it, she does not receive lashes, since in reality she is not a nezirah. In Rabbi Yehudah's view, even though she does not receive the forty lashes, she deserves makas mardus of rabbinic origin for her very intention to transgress the Torah.