Herbert Weir Smyth, A Greek Grammar for Colleges

Some verbs of saying admit other constructions than the infinitive, and especially ὅτι or ὡς (2579). λέγω, εἶπον, φράζω, φωνῶ with ὅτι or ὡς mean say, with the infinitive command (1997).

a. φημί say, assert, express the opinion that in classical Greek is almost always followed by the infinitive, but by ὅτι very often in the later language. φημὶ ὅτι occurs in X. A. 7.1.5 (φημὶ ὡς in L. 7.19, X. H. 6.3.7; D. 4.48, 27. 19 by anacoluthon).

b. λέγω state (impart a fact) takes either the infinitive or ὅτι or ὡς. The infinitive occurs usually with the passive (λέγεται, etc.) either in the personal or impersonal construction (1982 a). The active forms of λέγω with the infinitive mean command (1997).

c. εἶπον said usually takes ὅτι or ὡς; with the infinitive, it commonly means commanded (1997). Cp. the double use of told.

N.—εἶπον meaning said with the infinitive is rare, but occurs in good Attic prose: And. 1.57, 80; Thuc. 7. 35; Lys. 10. 6, 10. 9, 10. 12; Xen. H. 1. 6. 7, 2. 2. 15, C. 5. 5. 24, S. 2. 13; Is. 2.29; Lyc. 50; Aes. 3.37, 3. 59; Dem. 15. 18; Plato, G. 473 a, 503 d, Lach. 192 b, Charm. 174 a, Hipp. Maj. 291 b, Pol. 263 c, 290 b, L. 654 a, Clitoph. 409 a, 410 b. In poetry this use is frequent.