[ULPIANUS libro quadragensimo tertio ad Sabinum. ] §46.1.3.prQui satisdare promisit, ita demum implesse stipulationem satisdationis uidetur, si eum dederit accessionis loco, qui obligari potest et conueniri: ceterum si dederit seruum aut filium familias, ex quibus causis de peculio actio non datur, uel mulierem, quae auxilio senatus consulti utitur, dicendum est non esse impletam satisdationis stipulationem.
[ULPIANUS in the forty-third book on Sabinus.] A person who has promised to provide a security is deemed to have fulfilled the stipulation of security only if he has provided, in the place of an accessory, someone who can be legally bound and sued. On the other hand, if he has provided a slave or a son under paternal power, in whose case an action concerning peculiar property is not granted, or a woman who avails herself of the protection of the senate's decree, it must be said that the stipulation of security has not been fulfilled.
plane si non idoneum fideiussorem dederit, magis est, ut satisfactum sit, quia qui admisit eum fideiubentem, idoneum esse comprobauit.
Of course, if he has provided a surety who is not solvent, the better view is that the security has been satisfied, because the person who accepted him as a surety approved him as being solvent.