Shevuot 28B

שתיהן במזיד ⁠– אכליה לתנאיה והדר אכליה לאיסוריה, מיחייב; אכליה לאיסוריה והדר אכליה לתנאיה, פלוגתא דרבי יוחנן וריש לקיש ⁠– למאן דאמר התראת ספק שמה התראה, חייב; למאן דאמר לאו שמה התראה, פטור.

In a case where he ate both of them intentionally, if he ate the loaf whose consumption was his condition and then ate the forbidden loaf, he is liable to receive lashes. If he ate the forbidden loaf and then ate the loaf whose consumption was his condition, his liability is the subject of a dispute between R' Yoḥanan and Reish Lakish. According to the one who says that an uncertain forewarning is deemed a valid forewarning, he is liable to receive lashes. According to the one who says that an uncertain forewarning is not deemed a valid forewarning, he is exempt. Since when he was forewarned for eating the forbidden loaf it was uncertain whether it would actually become forbidden, that forewarning is not sufficient for him to be liable to receive lashes.

תלאן זו בזו ⁠– ״לא אוכל זו אם אוכל זו״, ״לא אוכל זו אם אוכל זו״; ואכל זו בזדון עצמה ובשגגת חבירתה, וזו בזדון עצמה ובשגגת חבירתה ⁠– פטור.

If one took an oath with regard to two loaves such that he rendered them interdependent, this one on that one, saying: I will not eat that if I eat this, and: I will not eat this if I eat that, and he ate this one intentionally with regard to itself, i.e., at the time he ate it he was aware that he had taken an oath that would render it forbidden if he ate the other, but unwittingly with regard to the other, i.e., he did not remember that in eating it he rendered the second one forbidden, and then he ate that one intentionally with regard to itself but unwittingly with regard to the other, he is exempt, as both conditions were fulfilled only unintentionally.