The writer of a letter sometimes puts himself in the place of his reader and describes as past that which is to himself present, but which will be past to his reader.
Eph. 6:22; ὃν ἔπεμψα πρὸς ὑμᾶς εἰς αὐτὸ τοῦτο, whom I send to you for this very purpose. See also Acts 23:30; 1 Cor. 5:11; Phil. 2:28; Col. 4:8; Philem. 11.