The headword has the archaic locative ending -thi.
[1] Likewise or similarly in other lexica; references at Photius omicron94 Theodoridis. The headword is taken to be quoted from Homer, Iliad 8.513.
[2] Several of the paroemiographers have this proverb but gloss it differently: "in reference to those providing witnesses against themselves". *oi)/koqen o( ma/rtus (without the full stop) occurs in Lucian, Juppiter tragoedus; Adler's typography suggests that she considered oi)/koqen alone to be the original Suda reading, with "proverb" and "witness etc." as later interpolations.