Stipulationum libri
Ex libro IV
Dig. 45,1,138Idem libro quarto stipulationum. Eum, qui certarum nundinarum diebus dari stipuletur, primo die petere posse Sabinus ait: Proculus autem et ceteri diversae scholae auctores, quamdiu vel exiguum tempus ex nundinarum spatio superesset, peti posse existimant. sed ego cum Proculo sentio. 1Cum pure stipulatus sum illud aut illud dari, licebit tibi, quotiens voles, mutare voluntatem in eo quod praestaturus sis, quia diversa causa est voluntatis expressae et eius quae inest.
The Same, Stipulations, Book IV. When anyone stipulates for something to be given to him on certain market-days, Sabinus says that he can demand it after the first day. Proculus, however, and other authorities of the rival school, think that it can be demanded as long as the smallest part of the market day specified remains. I agree with Proculus. 1When I stipulate absolutely, as follows, “Do you promise to give this, or that?” you can change your mind with reference to what you have to give, as often as you please; because there is a difference between an intention which is expressed, and one which is implied.