suae domui bene praepositum: filios habentem subditos cum omni castitate
The DRC1752 renders this into English as:
One that ruleth well his own house, having his children in subjection with all chastity.
I'm confused why domui appears to be dative? Isn't it the object of the verb, which would make it accusative (domum)?
Note the form of the verb: praepositum is a passive form, so it doesn't take a direct object. Specifically, it's a passive form of praeponō, "to put X in front of Y". This verb normally takes three arguments: the person doing the placing (nominative), the thing being placed (accusative), and what it's being placed in front of (dative).
In the passive, it becomes "to be put in front of Y", or metaphorically, "to have authority over Y". The thing you're in front of still goes in the dative, just like with the active forms. So praepositum domui suae means literally "having been put in front of his own house", or metaphorically "being in a position of authority over his own house" (that is, "ruling over his own house").
Because praeponere does not mean “rule.” It means (in this context) “to place or set over as chief, commander, or superintendent, to place at the head of, intrust with the charge or command of.” Note that praepositum is a passive form, meaning “who was placed at the head of,” and the subject of this mini-clause is actually the direct object of the verb. (He's in the accusative here because of the broader AcI context, but let's ignore that.)
But praeponere has not just a direct object (place whom in charge), but also an indirect object (in charge of what); so for example Pompeius Bibulum totae classi praeposuit means “Pompeius put Bibulus in charge of the whole fleet.”
The participle praepositus, -a, -um often loses the close association with the act of placing someone at the head of something, and more carries the idea of the resulting state of being at the head of something, meaning, in effect, “a prefect, president, head, chief, overseer, director, commander.” But in this context, it seems the verbal nature still predominates; hence the adverb bene.
