ἀφ' ἑαυτοῦ γνώμης
From LSJ
οὕτως ἐξ ἐχθρῶν αὐτοκτόνα πέμπετο δῶρα, ἐν χάριτος προφάσει μοῖραν ἔχοντα μόρου → thus mutual gifts that bring death were bestowed by enemies, gifts that brought the lot of death in the name of a favor
Greek > English (Woodhouse)
on his own initiative, on one's own authority, on one's own responsibility