Study Kiddushin folio 29B with parallel Hebrew-English text, traditional commentary, and modern study tools. Free access to Babylonian Talmud online.
Text Excerpt
כל היכא דליכא אלא חמש סלעים – הוא קודם לבנו. מאי טעמא? מצוה דגופיה עדיפא. כי פליגי היכא דאיכא חמש משועבדים וחמש בני חורין.
that anywhere that there are only 5 sela available, i.e., enough to redeem only one man, and one is obligated to redeem both himself and his son, he, the father, takes precedence over his son. What is the reason? It is that his own mitzva is preferable to one that he performs on behalf of others. When they disagree is in a case where there is land worth 5 sela that is liened property that has been sold, i.e., he sold this land to other people but it can be reclaimed by his prior creditor, and 5 sela which is entirely unsold property.
רבי יהודה סבר: מלוה (דכתיב) [הכתובה] בתורה ככתובה בשטר דמיא, בהני חמש פריק לבריה ואזיל כהן וטריף ליה לחמש משועבדים לדידיה.
And the reasoning behind the dispute is as follows: R' Yehuda maintains that a loan that is written in the Torah, i.e., any financial obligation that applies by Torah law, is considered as though it is written in a document, and therefore it can be collected from liened property, like any loan recorded in a document. This means that the liened property worth 5 sela is available for one’s own redemption, but not for that of his son, as the sale of the property occurred before the birth of his firstborn. Consequently, with these 5 sela upon which there is no lien he redeems his son, and the priest goes and repossesses the land worth 5 sela that is liened property for his own redemption. In this manner one can fulfill both mitzvot.
And the Rabbis maintain: A loan that is written in the Torah is not considered as though it is written in a document, since buyers will not be aware of this obligation, so that they should be aware that the land may be repossessed. And therefore there is no advantage for this man to redeem his son with the 5 sela upon which there is no lien, and his own mitzva is preferable, which means he redeems himself with the free land. With the liened property that is left he cannot redeem his son, as the land was sold before the birth of his firstborn.