My brother-in-law wanted to borrow my van to do carpool from camp. I asked him since he is going to the camp, if he can save me a trip and pick up my son (his nephew) too. He said he thought it might be ribis because I asked him to do a favor at the time of the loan. I claimed that close relatives don’t have ribis because we always do each other favors.
Who is right?
Essentially it is possible to have ribbis between relatives, but not for favors that would be done for each other regardless of the loan. In this case however there is no issue of ribbis because of a more basic reason. Ribbis only applies to a debt, or to money that was given in order for the borrower to use and pay back other money, however when an item is lent and it in itself has to be given back it isn’t ribbis. This is one of the reason why it is permitted to rent out cars apartments, etc. because the item itself is being returned.
Baba mEtzia 69b, Y:D176-1,2,3, Taz and Shach ibid 4.