[FLORENTINUS libro octavo institutionum. ] §45.1.65.prQuae extrinsecus et nihil ad praesentem actum pertinentia adieceris stipulationi, pro supervacuis habebuntur nec uitiabunt obligationem, ueluti si dicas: 'arma uirumque cano: spondeo', nihilo minus ualet.
[FLORENTINUS, Institutes, Book 8] Those things which you have added to a stipulation from the outside and which pertain nothing to the present act will be held as superfluous and will not invalidate the obligation; for example, if you should say, "Arms and the man I sing: I promise", it is nonetheless valid.
§45.1.65.1Sed et si in rei quae promittitur aut personae appellatione uarietur, non obesse placet: nam stipulanti denarios eiusdem quantitatis aureos spondendo obligaberis: et seruo stipulanti Lucio domino suo, si Titio, qui idem sit, daturum te spondeas, obligaberis.
But even if there is a variation in the designation of the thing promised or of the person, it is agreed that it does not stand in the way; for you will be bound by promising gold coins of the same value to one stipulating for denarii; and you will be bound to a slave stipulating for Lucius his master, if you promise that you will give to Titius, who is the same person.