Nedarim11: 8
הַמֻּדָּר הֲנָאָה מֵחֲתָנוֹ, וְהוּא רוֹצֶה לָתֵת לְבִתּוֹ מָעוֹת — אוֹמֵר לָהּ: ,,הֲרֵי הַמָּעוֹת הָאֵלּוּ נְתוּנִין לָךְ בְּמַתָּנָה, וּבִלְבַד שֶׁלֹּא יְהֵא לְבַעְלִיךְ רְשׁוּת בָּהֶן, אֶלָּא מַה שֶּׁאַתְּ נוֹשֵׂאת וְנוֹתֶנֶת בְּפִיךְ”.
One who is prohibited by a neder to benefit from his father-in-law, and he wants to give money to his daughter —- he says to her: “This money is given to you as a gift, provided that your husband has no rights in it, but that you put it in your mouth.”