The Messenger of Allah ﷺ said, "It is not permissible for a woman to give away any of her wealth as a gift once her husband holds the bond of marriage over her." The wording belongs to Muhammad.
أخبرنا محمد بن معمر قال حدثنا حبان قال حدثنا حماد بن سلمة ح و أخبرني إبراهيم بن يونس بن محمد قال حدثنا أبي قال حدثنا حماد بن سلمة عن داود وهو ابن أبي هند وحبيب المعلم
أن رسول الله ﷺ قال لا يجوز لامرأة هبة في مالها إذا ملك زوجها عصمتها اللفظ لمحمد
Grading, its chain of transmission is hasan. It was recorded by Abu Dawud in the Book of Business Transactions, chapter on a woman giving gifts without her husband's permission, hadith no. 3546, from the hadith of Hammad bin Salama, with this wording. It is also found in Al-Kubra, hadith nos. 6590 and 6589. Hakim graded it sahih at 2/47, and Dhahabi agreed with him. It has another route in Ibn Majah, hadith no. 2388, from Amr bin Shuayb, with this wording.