Aeschylus,
Agamemnon 1018-1021 (tr. Richmond Lattimore):
But when the black and mortal blood of man
has fallen to the ground before his feet, who then
can sing spells to call it back again?
τὸ δ᾽ ἐπὶ γᾶν πεσὸν ἅπαξ θανάσιμον
πρόπαρ ἀνδρὸς μέλαν αἷμα τίς ἂν
πάλιν ἀγκαλέσαιτ᾽ ἐπαείδων;
David Raeburn and Oliver Thomas,
The Agamemnon of Aeschylus: A Commentary for Students (Oxford: Oxford University Press, 2011), p. 177:
πρόπαρ is a rare
form of προπάροιθε. We take it as a preposition with ἀνδρός, since
the thought of Iphigenia's blood falling before Agamemnon would
appear to be near the front of the Chorus's mind. Alternatively
πρόπαρ is adverbial ('beforehand') and ἀνδρός depends on αἷμα.
Homicide (in contrast to hunger) is irremediable, even by the powers
of song. Similarly Cho. 48 'What payment can release blood once
it has fallen to the ground?', Eum. 261–3, and 647–8 'When the
dust has absorbed the blood of a man once dead, there is no rising
again.'
Related post:
Ineffectual Prayers.