Where there is a document attesting to a sale of a husband's property to his wife, the gemmarah says that we are concerned that perhaps he wrote the document only to encourage his wife to return to him money which was rightfully his and that she can not rely that in conjunction with a chazakah to claim that he did indeed sell her the property.
Why can she not have a migo that had she claimed that he had gifted her the property she would have been believed so too she should be believed when she claims that he sold it to her?
G Schreiber, Chicago
A Migo only helps when the question is whether or not a person is to be believed. In the case at hand, though, the woman has no lack of credibility; to the contrary, she has a Shtar. Rather, we void the sale because of the husband's claim of "Ligeluyai Zuzi."