Parshas Korach
The posuk 18:24 says that the leviim get maaser since they do not get an inheritance. In posuk 31 it says that they get maaser because they work in the ohel moed. Which one is it?
Maaser is one tenth. As they are one of the twelve tribes, they should have gotten 1/12 of Eretz Yisrael, instead they get 1/10 of the fruit. However 1/10 is more then 1/12, that is why the posuk gives the second reason that they work so they get extra.