If one is living on a property for a period of time and the original owner does not protest, if the one living on the property cannot produce documentation of ownership, but claims that he/she bought the land or was given it as a gift, that is enough to prove ownership as one cannot be expected to save documentation for a long period of time. How much time is generally 3 years however it depends on what type of property and what signs of ownership. Rabbi Yishmael holds that it is sufficient to have 3 harvests of different types of fruits, that would be sufficient. Also how to calculate 3 years depends of the type of land – three full years or parts of the first and last year with a whole year in the middle. The gemara then attempts to derive the source for 3 years/harvests. Two answers are brought – one a comparison to a shor muad and another learned out from a verse in Yirmiyahu where he tells the people to buy land and write documents and save them as they will only be in the land for two years – assumption: if it were 3, there would be no need for documentation. The gemara questions the first interpretation however brings answers – although in the end, the comparison only works for Rabbi Yishmael’s opnion. The Yirmiyahu proof is rejected as it is said that it can be viewed as good advice only and not as halacha.