Kiddushin 19B

וכי משייר בה שוה פרוטה ומייעד ⁠– הוו קידושין, הכא נמי לא שנא.

And yet if time for her to perform work worth one peruta remains, and he designates her, it is a betrothal. This shows that he can betroth her with a loan, i.e., the value of the remaining time of her servitude, for which she herself is collateral. Here too, it is no different, and in general one may betroth a woman with a loan for which there is collateral.

תנו רבנן: כיצד מצות יעוד? אומר לה בפני שנים ״הרי את מקודשת לי״, ״הרי את מאורסת לי״ אפילו בסוף שש, ואפילו סמוך לשקיעת החמה. ונוהג בה מנהג אישות ואינו נוהג בה מנהג שפחות. רבי יוסי ברבי יהודה אומר: אם יש שהות ביום כדי לעשות עמו שוה פרוטה ⁠– מקודשת, ואם לאו ⁠– אינה מקודשת.

§ A baraita states: How is the mitzva of designation performed? The master says to her before two witnesses: You are hereby betrothed [mekuddeshet] to me, or: You are hereby betrothed [me’oreset] to me. The designation is effective even if he said this at the end of 6 years of work, and even if it is close to sunset on the last day of her term. And once he designates her he treats her in the manner of marriage and may not treat her in the manner of slavery. R' Yosei, son of R' Yehuda, says: If there is enough time left in that day for her to perform for him work worth one peruta, she is betrothed, and if not, she is not betrothed.

משל לאומר לאשה ״התקדשי לי מעכשיו לאחר שלשים יום״ ובא אחר וקידשה בתוך שלשים יום ⁠– שמקודשת לראשון. משל למאן?

The baraita continues: This can be understood by way of a parable comparing this halakha to the halakha of one who says to a woman: Be betrothed to me from now after 30 days, and another man came and betrothed her within 30 days. In this case the halakha is that she is betrothed to the first man. The Talmud inquires: According to whom is this parable suggested? Of the two opinions cited in the baraita, whose opinion accords with the halakha in the case of the parable?