- שבועת ביטוי even applies to דברים שאין בהן ממש (sleeping, throwing)
The next Mishnah teaches the applications of שבועת ביטוי – an oath of “utterance” (which obligates a korban). It takes effect whether he swears about דברים של עצמו – matters pertaining to himself, or דברים של אחרים – matters pertaining to others, such as swearing “I will give [something] to Ploni,” or that he will not give him, or already did or did not give him. It also applies to דברים שאין בהן ממש – matters which have no substance. The Mishnah provides examples of two categories of this principle: one who swears "שאישן" – that I will sleep, or I will not sleep, or already did or did not sleep (which is intangible), or one who swears "שאזרוק צרור לים" – that I will throw a stone into the sea, etc., which benefits no one. Rebbe Yishmael holds there is only a korban for a shevuah made about the future, based on the passuk’s language, but Rebbe Akiva darshens to include shevuos about the past. This machlokes is explained on the next Daf.
- שבועה שזרק פלוני צרור לים (which lacks a future form)
If someone (falsely) swore "שזרק פלוני צרור לים" – that Ploni threw a stone into the sea (or did not), Rav says it obligates a korban, since this shevuah can be made בלאו והן – both in the negative and in the positive form. Shmuel says he is exempt, because ליתיה בלהבא – it lacks a valid future form, since swearing, “Ploni will (or will not) throw a stone,” is a שבועת שוא – a vain shevuah (since that person’s actions are out of his control). This machlokes is explained in two ways: (1) They argue according to Rebbe Akiva, who obligates a korban even for a past-tense shevuah. Still, Shmuel says Rebbe Akiva only holds this for מלתא דאיתא בלהבא – a matter which has a valid future form; this shevuah, which lacks a future form, is even exempt for the past form. (2) They argue according to the Rabbonon (on Daf 27a) who exempt one who violates a shevuah to fulfill a mitzvah, because it lacks a valid negative form (since swearing to violate a mitzvah is ineffective). Still, Rav says they only require לאו והן – a negative and positive form, which the passuk explicitly mentions, but not future and past forms, since a past-tense shevuah is only derived from a derashah.
- Why the Torah created a category of שבועת העדות, which is included in שבועת ביטוי
According to Shmuel, it is understood why the Torah created a new category of שבועת העדות – swearing (falsely) about not knowing testimony, because since it lacks a future form (one cannot swear that he will or will not know testimony), it would not obligate a korban without this passuk. But according to Rav, who does not require a future form, why did the Torah need to establish this category? Rabbis suggested to Abaye that the Torah is obligating a second korban, but Abaye quoted a Baraisa darshening that שבועת העדות is only liable for one korban. Instead, the Gemara answers that the Torah taught this category (which does not say "ונעלם" – and [his sin] was concealed [from him], in contrast to other korbanos), to teach that שבועת העדות is uniquely liable for a korban even במזיד.
Rava says that even without a passuk, שבועת העדות cannot be liable twice, because after it was made a distinct category, it was entirely removed from the category of שבועת ביטוי. [Rashi says the נפקא מינה would be an invalid witness who swears, or one who swears outside of Beis Din, whether he would be liable for שבועת ביטוי.]
