TT #696 · Parashas Ki Seitzei · Seventh Aliyah · Passuk 25:06
And it shall be that the firstborn that she bears shall succeed to the name of his dead brother, so that his name shall not be blotted out from Israel.
Torah Temimah points to Yevamot 24a / Sifrei.
TT lemma: עַל שֵׁם אָחִיו.
עַל שֵׁם אָחִיו – לְנַחֲלָה, וְלֹא שֶׁאִם הָיָה שְׁמוֹ יוֹסֵף קוֹרִין אוֹתוֹ יוֹסֵף.
English: “To the name of his brother” — with respect to inheritance, and not that if the deceased’s name was Yosef they call the child Yosef.
On the daf / in context: The derashah rejects the simple reading that the child must be given the deceased’s personal name; the “name” is the inheritance share.
Derash defining “name” as inheritance rather than personal name.
The obligation is to establish the deceased’s inheritance share, not to give the child the deceased’s personal name.