manu misit: here Cicero pauses to reply to an argument on the other side. Only slaves could be forced to give testimony by torture (Rosc. Am., sect. 35). As Milo had freed his, it was maintained by the prosecution that he wished to destroy evidence. Manumission under such circumstances was forbidden by later law.
indagamus hic, i.e. the legal aspect of the case is to be considered at this point.
nescis, you know not how: ยง 456 (27 i) ; B. 328, I ; G. 423 ; H. 607 (533); H.-B. 586.