When Abraham hesitates, the Holy One settles it with a line that should be underlined in every copy of the Torah. In Targum Pseudo-Jonathan on Genesis 21:12, the Aramaic makes the reasoning plain: Hearken unto all that Sarah saith to thee, because she is a prophetess.
The Hebrew text says only, listen to her voice. The Targum adds the title. Sarah is a nevi'ah, a prophetess — and her prophetic rank is the reason Abraham must obey her even when her command feels wrong.
The tradition is preserved in the Babylonian Talmud (Megillah 14a), which lists seven prophetesses in Israel: Sarah, Miriam, Deborah, Hannah, Abigail, Huldah, and Esther. Pseudo-Jonathan integrates that teaching directly into the verse itself.
The Targum of Pseudo-Jonathan then clinches the inheritance question: in Isaac shall sons be called unto thee; and this son of the handmaid shall not be genealogized after thee. The covenant line is settled.
The Maggidim took this as a rebuke to every household that underestimates the women within it. When your wife sees what you cannot, the takeaway is not to argue. It is to listen.