φέρουσα κατακρύπτει ἐς τὸ ἀφραστότατόν οἱ ἐφαίνετο εἶναι → wherefore she bore it away and hid it where she thought it would be hardest to find
dat. pl. de ὕδωρ.
ὕδασι: dat. pl. к ὕδωρ.