וַיַּ֨עַן הַמֶּ֜לֶךְ וַיֹּ֗אמֶר תְּנוּ־לָהּ֙ אֶת־הַיָּל֣וּד הַחַ֔י וְהָמֵ֖ת לֹ֣א תְמִיתֻ֑הוּ הִ֖יא אִמּֽוֹ׃
Tedy odezwał się król, i rzekł: Oddajcie jej to dziecię żywe, a nie zabijajcie go; ta jest matka jego!
Tze'enah Ure'enah
“The king responded: give her the live child, etc.” [3:27]. The king said: give her the live child and the child should not be killed, since this is his mother. The Midrash writes that a Heavenly voice went forth and said: this is his mother. That is to say, that Solomon had judged correctly.4Genesis Rabbah, 85.12.
Rashi
She is his mother. A Divine voice appeared and said, “She is his mother.”26See Rashi in Maseches Makos 23b.