1. BDAG, s.v. ἔχω 7.a.d.
2. See Klauck and Bailey, Ancient Letters; Exler, The Form of the Ancient Greek Letter; John L. White, Light from Ancient Letters (Philadelphia: Fortress, 1986).
3. For instance, P.Iand. 9(42); P.Oxy. I.123 (190); cf. Loeb, Select Papyri, 334, 376.