Tractate Nedarim - Chapter 10 - Mishnah 7 נדרים פרק י׳ משנה ז׳

If a man says to his wife, “All vows which you may vow from now until I return from such and such a place behold, they are upheld,” he has not said anything. [If he said: All vows which you may vow from now until I return from such and such a place], behold, they are annulled,”: Rabbi Eliezer says: they are annulled; The Sages say: they are not annulled. Said Rabbi Eliezer: if he can annul vows which have already had the force of a prohibition, surely he can annul those which have not had the force of prohibition! They said to him: behold, it is said, “Her husband may uphold it, and her husband may annul it” (Numbers 30:14), that which has entered the category of upholding, has entered the category of annulment; but that which has not entered the category of upholding, has not entered the category of annulment.