[IDEM libro septimo disputationum. ] §18.1.38.prSi quis donationis causa minoris uendat, uenditio ualet: totiens enim dicimus in totum uenditionem non ualere, quotiens uniuersa uenditio donationis causa facta est: quotiens uero uiliore pretio res donationis causa distrahitur, dubium non est uenditionem ualere.
[THE SAME, in the seventh book of Disputations.] If anyone should sell at a lower price for the purpose of donation, the sale is valid; for we say that a sale is invalid as a whole only as often as the entire sale has been made for the purpose of donation; but as often as a thing is sold at a lower price for the purpose of donation, there is no doubt that the sale is valid.
hoc inter ceteros: inter uirum uero et uxorem donationis causa uenditio facta pretio uiliore nullius momenti est.
This applies among other persons; but a sale made between husband and wife at a lower price for the purpose of donation is of no validity.