Shevuot 35A

להכי כתבה רחמנא לעדות גבי שבועת ביטוי וגבי טומאת מקדש וקדשיו ⁠– דבכולן נאמר בהן ״ונעלם״, וכאן לא נאמר בהן ״ונעלם״; לחייב על המזיד כשוגג.

The Talmud answers: For that reason, God writes the verse with regard to an oath of testimony near the verse with regard to an oath on an utterance and near the verse with regard to the defiling of the Temple or its sacrificial foods, as in all of those passages it is stated concerning them: “And it is hidden,” and here, with regard to an oath of testimony, it is not stated concerning them: And it is hidden. The Torah did so to underscore the contrast between them and to deem liable one who takes an intentional false oath of testimony like one who takes an unwitting false oath of testimony.

מתני׳ ״משביע אני עליכם, אם לא תבואו ותעידוני שאמר איש פלוני ליתן לי מאתים זוז ולא נתן״⁠ – הרי אלו פטורים, שאין חייבין אלא על תביעת ממון כפקדון.

Mishnah: If one said to witnesses: I administer an oath to you concerning your refusal to testify if you do not come and testify on my behalf that so-and-so said he is going to give me 200 dinars and he did not give them to me, and they take false oaths that they have no knowledge of the matter, they are exempt from liability to bring an offering for taking a false oath of testimony, as one is liable for taking a false oath of testimony only in a case involving a monetary claim like a deposit in the sense that were the witnesses to testify, the individual would be liable to pay. In the case of a promise to give a gift he could claim that he merely reconsidered.

״משביע אני עליכם כשתדעו לי עדות שתבואו ותעידוני״⁠ – הרי אלו פטורים, מפני שקדמה שבועה לעדות.

If one said to witnesses: I administer an oath to you that when you will know testimony relevant to me you will come and testify on my behalf, these witnesses are exempt from liability for taking a false oath of testimony even if they do not testify, due to the fact that the oath preceded their knowledge of the relevant testimony.