Reference for Yevamot 134:6

מה נפשך אי האי דמעברא בן הוא לא עדיף מהאי דקאי אי בת היא אמאי אכלה בתקנתא דרבנן כמה דלא נפק לאויר העולם לא תקינו רבנן

as well as a daughter, [so that the slaves may eat the <i>terumah</i>] whatever be the assumption [as to the sex of the embryo]. If the embryo is a son then he is not better than the one who is already born.<span class="x" onmousemove="('comment',' Lit., 'exists', 'stands'. Since the Rabbis deprived the living son of his share and gave it to the daughters. they have, even more so, deprived the embryo of its share. ');">¹⁶</span> And if it is a daughter, then why does a daughter eat at all?<span class="x" onmousemove="('comment',' From her father's estate, though he is also survived by sons' ');">¹⁷</span> Surely by virtue of an ordinance of the Rabbis.<span class="x" onmousemove="('comment',' Pentateuchally she has no claim at all in the presence of a son. ');">¹⁸</span>

Jastrow