Versions of this proverb appear in several of the paroemiographic collections e.g. Appendix Proverbiorum 1.54 ( = E.L. Leutsch and F.G. Schneidewin, Paroemiographi Graeci, vol. 1, appendix, p. 387, no. 54), where the verb is in the second person singular, and the post-Suda Michael Apostolius (4.90). Common to the non-Suda versions is that the proverb itself is confined to the first two words, i.e. "as if gaping" is part of the gloss.
Besa(s) occurs in Eusebius and elsewhere as an Egyptian god.