τὸ δ' ἐξαίφνης τὸ ἐν ἀναισθήτῳ χρόνῳ διὰ μικρότητα ἐκστάν → suddenly refers to what has departed from its former condition in a time imperceptible because of its smallness
οἷα: «ὥσπερ, καθάπερ» Ἡσύχ.
plur. neutre de οἷος.