Gittin 51 - Suing for the value of the land

If someone buys land which is later found to be stolen and the original owner repossesses it, the deceived buyer can sue the seller (thief) for the amount. However, he can not sue for the crop which was on the land - because this obligation was not fixed and thus was not guaranteed by the seller (thief).

If someone is returning a lost object and the owner claims that not everything is returned, then it is decreed that the finder does not have to take an oath to his truthfulness - so that the people should not refrain from returning found objects.