Midrash · Halachah
Sifrei Devarim 216/ספרי דברים רט״ז
א(דברים כא טז) וְהָיָה בְּיוֹם הַנְחִילוֹ אֶת בָּנָיו, בַּיּוֹם מַפִּילִים נַחֲלוֹת וְאֵין מַפִּילִים נַחֲלוֹת בַּלַּיְלָה.
1Pisqa’ 216221. “So when the day comes to bequeath to his sons” (Dt. 21:16).Bequests are distributed by day,but they are not distributed by night.
באֵת אֲשֶׁר יִהְיֶה לוֹ, מְלַמֵּד שֶׁהַבֵּן נוֹטֵל בָּרָאוּי כְּבַמֻּחְזָק.
2“That which is to be his” (Dt. 21:16)—is to be his, teaches that the son takes,as his inheritance from his father’s estate,both its anticipated income and its current holdings.23 217.4.
גלֹא יוּכַל לְבַכֵּר, מְלַמֵּד שֶׁאֵינוֹ רַשַּׁי לְבַכֵּר. יָכוֹל לֹא יְבַכֵּר, וְאִם בִּכֵּר – יְהֵא מְבֻכָּר? תַּלְמוּד לוֹמַר: לֹא יוּכַל לְבַכֵּר, הָא אִם בִּכֵּר – אֵינוֹ מְבֻכָּר.
32. “He is unable to transfer the right of the First-born” (Dt. 21:16)—this teaches that the father hasno right to transfer the status of the First-born[to another son by a different wife].Is it possible to say that,while the father has no right to transfer the status of the First-born,if he does so, it is done?The Teaching states:“He is unable to transfer the right of the First-born” (Dt. 21:16)—thus, if the father does transfer this status,it is not [effectively] done.
דאֶת בֶּן הָאֲהוּבָה, כֵּיוָן שֶׁיָּצָא רֹאשׁוֹ וְרֻבּוֹ בַּחַיִּים – פּוֹטֵר אֶת הַבָּא אַחֲרָיו מִן הַבְּכוֹרָה.
4“To the son of the favored wife” (Dt. 21:16)—as soon as the First-born’s headand most of his body emerge alive,he exempts any brother born after him[even of a different mother]from [exercising the right of] the First-born.
העַל פְּנֵי בֶן הַשְּׂנוּאָה הַבְּכֹר – אַף עַל פִּי שֶׁבֵּן הַבְּכוֹר לַשְּׂנוּאָה.
5“Instead of to the son of the rejected wife, the rightful First-born” (Dt. 21:16)—even though the First-born son belongs to the rejected wife,[his father cannot transfer First-born status to his son by a favored wife].