ἐπὶ ξυροῦ γὰρ ἀκμῆς ἔχεται ἡμῖν τὰ πρήγματα → our affairs are balanced on a razor's edge, our affairs are set upon the razor's edge
from πρό and αἱρέομαι; to choose for oneself before another thing (prefer), i.e. (by implication) to propose (intend): purpose.
