Redeeming the Firstborn Past the Thirtieth Day

How the Gemara uses a verbal analogy to establish the exact timing and currency standard for redeeming a firstborn son.

וּפְדוּיָו֙ מִבֶּן־חֹ֣דֶשׁ תִּפְדֶּ֔ה בְּעֶ֨רְכְּךָ֔ כֶּ֛סֶף חֲמֵ֥שֶׁת שְׁקָלִ֖ים בְּשֶׁ֣קֶל הַקֹּ֑דֶשׁ עֶשְׂרִ֥ים גֵּרָ֖ה הֽוּא׃

Take as their redemption price,gtheir redemption price I.e., for human first-born; cf. 3.44ff. For animals, see Exod. 34.19–20. from the age of one month up, the money equivalent of five shekels by the sanctuary weight, which is twenty gerahs. (Numbers 18:16)

The Torah Setting and Plain Meaning

In Parashat Korach, the Torah delineates the designated gifts given to Aharon and the priests. Among these sacred dues, every firstborn male must be consecrated to God. While kosher animals are sacrificed on the altar, human firstborns must be redeemed with money.

The verse specifies that the father must redeem his newborn son from one month of age for five silver shekels. Ibn Ezra clarifies that the opening word of the verse, וּפְדוּיָו, refers exclusively to human firstborn sons rather than animals. In its plain sense, the verse establishes an age threshold of one month and fixes the redemption price.

The Ambiguity of One Month

The Torah requires the redemption to take place from the age of one month, phrased as מִבֶּן־חֹדֶשׁ. However, this phrasing leaves the precise operational moment uncertain. Does the mitzva take effect on the thirtieth day itself, or must the father wait until the thirtieth day has completely elapsed?

This question determines whether a redemption performed on the thirtieth day is valid. A newborn who survives thirty full days ceases to be a ספק נפל (doubtful non-viable infant). The Gemara must clarify whether the Torah permits redemption as soon as the thirtieth day arrives or only once it concludes.

The Verbal Analogy to the Wilderness

To resolve the ambiguity, the Rabbis apply a גזירה שוה (verbal analogy) linking two passages. They connect the perpetual command of redemption to the historical census of firstborns in the wilderness. Both verses employ the word חֹדֶשׁ (month) to designate the relevant milestone.

In the wilderness census, the text explicitly commands Moses to count every firstborn male from a month old וָמָעְלָה (and upward). Rashi explains that the term וָמָעְלָה indicates that the action occurs strictly after thirty days have elapsed. By virtue of the verbal analogy, the perpetual redemption of sons likewise requires thirty full days to have passed.

גְּמָ׳ מַאי טַעְמַיְיהוּ דְּרַבָּנַן? גָּמְרִי ״חֹדֶשׁ״ ״חֹדֶשׁ״ מִמִּדְבָּר, מָה הָתָם ״וָמַעְלָה״ אַף הָכָא נָמֵי וָמַעְלָה.

What is the reason of the Rabbis? They derive 'month' from 'month' in the wilderness: just as there 'and upward' is stated, so too here 'and upward' applies. (Bekhorot 49a:6)

Rabbi Akiva and Two Overlapping Verses

Rabbi Akiva questions this derivation due to a hermeneutical complication. The Torah explicitly writes וָמַעְלָה (and upward) regarding the laws of ערכין (valuations) in Leviticus. If the wilderness census already established that a month or year means upward, the verse in ערכין appears entirely redundant.

Under rabbinic hermeneutics, when two verses teach the same law, they become שְׁנֵי כְתוּבִים הַבָּאִים כְּאֶחָד (two verses that come as one). Such verses cannot teach their common rule to external subjects. Because of this principle, Rabbi Akiva remained uncertain whether the thirtieth day in firstborn redemption is treated like the days before it or the days after it.

ומעלה - משמע לאחר שלשים

'And upward'—implies after thirty days. (Rashi on Bekhorot 49a:6:2)

The Currency Standard for Redemption

The verse also dictates the financial metric of redemption: five silver shekels according to the sanctuary standard. The Mishnah rules that these five sela coins must be evaluated using a Tyrian maneh. Tyrian coinage contains high silver purity, far exceeding provincial coins.

Rashi notes that the sanctuary shekel equals twenty ma'ot of Tyrian silver. All monetary penalties and redemptions mentioned in the Torah must meet this Tyrian silver standard. The obligation cannot be discharged with inferior provincial currency.

מַתְנִי׳ חָמֵשׁ סְלָעִים שֶׁל בֵּן — בְּמָנֶה צוֹרִי.

Mishnah: The five sela coins of the son are calculated using a Tyrian maneh. (Bekhorot 49b:10)

The Practical Halachic Conclusion

The Gemara establishes that the redemption of a firstborn son can take place only on the thirty-first day or later. If a father pays the kohen on the thirtieth day itself, the redemption is invalid according to the Rabbis. The child must complete thirty full days of life before redemption.

Furthermore, Rav Ashi notes that all authorities agree regarding אֲבֵילוּת (mourning) that the thirtieth day is treated like the preceding days. If an infant dies on his thirtieth day, he maintains the status of a doubtful stillborn, and mourning rites are not observed. Only once thirty full days have passed does the child attain definitive viability and require redemption.

A firstborn son is redeemed only after thirty full days have passed, using five silver shekels of Tyrian standard.

Learn Bekhorot 49 on Super Daf