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
κεῖσο: κείσθω, βʹ και γʹ ενικ. προστ. του κεῖμαι.
