a. A poetical genitive occurs rarely in exclamations, in imitation of the Greek (Genitive of Exclamation):
b. The genitive is often used with the ablatives causá, gratiá, for the sake of; and the indeclinable ínstar, like; also with prídié, the day before; postrídié, the day after; tenus, as far as:
NOTE 1: Of these the genitive with causá is a development from the possessive genitive and resembles that in nómen ínsániae (§ 343. d.). The others are of various origin.
NOTE 2: In prose of the Republican Period prídié and postrídié are thus used only in the expressions prídié (postrídié) êius diéí, the day before (after) that (cf. ``the eve, the morrow of that day''). Tacitus uses the construction with other words: as, - postrídié ínsidiárum, the day after the plot. For the accusative, see § 432. a. Tenus takes also the ablative (§ 26).