Rif Ketubot 37b {Ketubot 79a}

37b

{Ketubot 79a}

מיתיבי הרוצה שתבריח נכסיה מבעלה כיצד היא עושה כותבת שטר פסים לאחר דברי ר' שמעון [ב"ג] וחכ"א רצה משחק בה עד שתכתוב לו מהיום ולכשארצה
טעמא דכתבה ליה הכי הא לא כתבה ליה הכי קננהו לוקח
א"ר זירא ל"ק הא בכולן הא במקצתן במקצתן עד דכתבה ליה הכי אבל בכולן אפי' לא כתבה לו הכי לא קננהו
כדגרסי' בפ' מי שמת חמשה עד שיכתבו כל נכסיהן וחדא מינייהו המברחת נכסיה מבעלה ואי לא קננהו לוקח נקנינהו בעל
אמר אביי עשאום כנכסים שאין ידועין לבעל ואליבא דר' שמעון
ושמעינן מינה דהלכתא כר' שמעון

They objected: If she wants to keep her assets away from her husband, how should she act? She writes a contract of trust to another {=to a stranger}. These are the words of R' Shimon [ben Gamliel]. And the Sages say: If he wishes, he {=the deed-holder} may laugh at her, until she writes to him from today, and when I wish.
The reason is that she wrote to him such. Thus, if she did not write to his thus, the buyer would acquire!
Rabbi Zera said: This is no question. Here is by all of them, while here is by some of them. By some of them, until she writes him such. But all of them, even if she writes him such, he does not acquire them. As we learn in perek mi shemet, "Five, until they write all of their assets," and one of them is the woman who wishes to keep her assets away from her {future} husband, and if the buyer does not acquire them, the husband acquires them.
Abaye said: They {assets which are thus fictitiously transferred} are made {treated} like assets which are not known to the husband, and according to Rabbi Shimon.
And we deduce from here that the halacha is like Rabbi Shimon.

Mishna:

נפלו לה נכסים ילקח בהן קרקע והוא אוכל פירות פירות התלושין מן הקרקע ילקח בהן קרקע והוא אוכל פירות

If assets fell to her {the married woman}, land should be purchased with it, and he should eat the fruits. If {what fell to her was} fruits separated from the ground, land should be purchased with it and he should eat the fruits.