Their proof is a proof and we place the field in their possession - ראייתן ראיה ומעמידין שדה בידן
Summary:
The double ruling that אין ראייתו ראיה and אין מעמידין שדה בידו teaches us that not only does the גזלן not receive the field, but he also does not get back any money (where it was merely אודי ליה).
אבל בשטר קנה –However he acquires it with a note -
Summary:
In the case of לקח מן האיש ואח"כ לקח מן האשה it is a valid sale if the שטר was only לראיה and another קנין was made previously, or a שטר is always valid, or a שטר is valid if it is a separate שטר from her husband’s.