ἅμα κνέφᾳ

From LSJ

Τοὺς δούλους ἔταξεν ὡρισμένου νομίσματος ὁμιλεῖν ταῖς θεραπαινίσιν → He arranged for his male slaves to have sex with female slaves at a fixed price (Plutarch, Life of Cato the Elder 21.2)

Source

Dutch (Woordenboekgrieks.nl)

bij dageraad Xen. Cyr. 4.2.15.