We learnt the other day in Daf Yomi that if someone lived a field for 3 years and claims that someone sold it to him doesnt need a Shtar because we assume that someone would've said something if he was living there for so long. But maybe he rented it from someone? How can he prove that?
Gmar Vachasimah Tova
Aaron Pacanowski
The Gemara in Bava Basra 35b says that if a person lets someone else eat the fruit of his land, for example to pay off a debt or because he has sold the rights to the fruit, he must be Mocheh at least once every three years. Failure to do so will mean that the one eating the fruit can claim that he bought the field. The same will apply to someone who rented out his property.
The Ramban (ibid.) explains that the Chachamim instituted that after three years we believe the Machzik that he bought the property, because normally the original owner would have objected within three years had he not sold it. The Chachamim also said that the onus is on the owner to object in cases where they allow fruit to be eaten for three years without having sold the actual property, because otherwise the owner would always be able to claim that he had only sold the fruit.
Dov Freedman