[GAIUS libro nono ad edictum prouinciale. ] §15.3.12.prSi fundum patri dominoue emit seruus uel filius familias, uersum quidem esse uidetur, ita tamen, ut, siue minoris sit, quam est emptus, tantum uideatur in rem uersum quanti dignus sit, siue pluris sit, non plus uideatur in rem uersum quam emptus est.
[GAIUS, On the Provincial Edict, book 9] If a slave or a son-in-power buys a tract of land for his father or master, it indeed seems to have been turned to profit, yet only in such a way that, if its value is less than the price for which it was bought, only so much is deemed to have been turned to profit as it is worth; but if its value is more, no more is deemed to have been turned to profit than the price for which it was bought.