That is, instead of the headword's foreshortened ni/fa -- which is, however, an authentic accusative of a noun meaning snow, from the root *snighw-, cf. nu 294, alpha 144, nu 363. This headword phrase occurs in Hesiod, Works and Days 535 (web address 1).
To call something 'from Kekrops' (the early Athenian king: see alpha 268, alpha 3838, alpha 3863, delta 1492, kappa 1269, kappa 1271, kappa 1410) is evidently akin to our saying 'out of the Ark' or suchlike.
[1] See nu 437.