Same entry in Photius (rho14 Theodoridis); and cf. Hesychius rho1, who glosses w(s r(a/ with w(s dh/.
The enclitic particle r(a/ "is found in Epic and also in lyric poets and the lyrics of tragedy" (Denniston 32, under a)/ra).
[1] Adler notes, without comment, the suggestion of S.A. Naber that this gloss should refer to Plato the comic poet (pi 1708), not his namesake the philosopher (pi 1707, pi 1709). Theodoridis documents the matter more fully, noting the suggestion of Kassel-Austin at their Plato Comicus fr. 301; they cite Plato, Republic 3.386D (a quotation of Homer, Iliad 23.103).