[IDEM libro singulari de officio praefecti uigilum. ] §20.2.9.prEst differentia obligatorum propter pensionem et eorum, quae ex conuentione manifestari pignoris nomine tenentur, quod manumittere mancipia obligata pignori non possumus, inhabitantes autem manumittimus, scilicet antequam pensionis nomine percludamur: tunc enim pignoris nomine retenta mancipia non liberabimus: et derisus Nerua iuris consultus, qui per fenestram monstrauerat seruos detentos ob pensionem liberari posse.
[THE SAME, in his single book on the Office of the Prefect of the Watch.] There is a difference between things obligated on account of rent and those which are held under the name of a pledge clearly by agreement, in that we cannot manumit slaves pledged to a creditor, whereas when we are tenants we do manumit them, provided of course it is before we are shut out on account of the rent: for then we shall not free the slaves retained under the name of a pledge. And Nerva the jurist was ridiculed, who had pointed out that slaves detained on account of rent could be manumitted through a window.