Photius, Epistulae et Amphilochia 56 (γλῶσσα τοῦ πνεύματος
 καὶ τῆς ὑπὲρ λόγον σοφίας καὶ γνώσεως ὄργανον·); Theognostus, Canones sive De orthogrqphia 492 (Τὸ γλῶσσα γέγονεν οὕτως· ὥσπερ ἀπὸ τοῦ ὀγδοήκοντα, ὀγδώκοντα, κατὰ κρᾶσιν τοῦ ο καὶ η εἰς ω μέγα, οὕτω καὶ παρὰ τὸ νοήσω, νώσω, καὶ ἐκ τούτου νῶσσα, καὶ πλεονασμῷ τοῦ γ γνῶσσα, καὶ τροπῇ τοῦ ν εἰς λ γλῶσσα); Joannes Mauropus, Etymologica nominum 177 (γνῶσιν κομίζει γλῶσσα τῶν ἐν καρδίᾳ); Etym. Gudianum, gamma p. 314 (Γλῶσσα· παρὰ τὸ γνῶ γνῶ‹σ›σα καὶ γλῶσσα, ὡς διαγνωστικὴ οὖσα τῶν χυμῶν); Etym. Gudianum Additamenta, gamma p. 315 (Γλῶσσα· παρὰ τὸ εἶναι αὐτὴν γνῶσιν τῶν νοστίμων καὶ ἀνόστων, ἤγουν τῶν βρωσίμων καὶ ποσίμων, ἡδέων καὶ πικρῶν, γλυκέων καὶ ἀγλύκων ; ibid. Γλῶσσα· τὸ φωνητικὸν ὄργανον παρὰ τὸ γνώσω γνῶσα καὶ πλεονασμῷ τοῦ ς γνῶσσα καὶ γλῶσσα, ἡ ὑπὸ γνῶσιν ἄγουσα τὰ ἐν τῇ διανοίᾳ ; ibid. Γλῶσσα· τρέψας τὸ λ εἰς τὸ ν καὶ τὸ δεύτερον ς εἰς τὸ τ φημὶ οὕτως ἡ  γνωστὰ ἐν τῷ νῷ τοῖς ἀκούουσι ποιοῦσα τὰ λεγόμενα); Etym. Magnum, Kallierges p. 235 (Γλῶσσα· παρὰ τὸ γνῶ γνώσω γνῶσα καὶ γλῶσσα, ἡ ὑπὸ γνῶσιν ἄγουσα τὰ ἐν τῇ διανοίᾳ· ἢ  δι’ ἧς τὰ τῆς ψυχῆς βουλεύματα γινώσκομεν).

This etymology may be implicit in Xenophon, Memorabilia 1, 4, 5 (τίς δ’ ἂν αἴσθησις ἦν γλυκέων καὶ δριμέων καὶ πάντων 
τῶν διὰ στόματος ἡδέων, εἰ μὴ γλῶττα τούτων γνώμων
 ἐνειργάσθη; "What perception should we have of sweet and bitter and all things pleasant to the palate had we no tongue in our mouth to discriminate between them?"); repeated in Plutarch, Mor. 990a5-6 (ἡ μὲν γὰρ γλῶττα τοῦ γλυκέος καὶ δριμέος καὶ αὐστηροῦ γνώμων ἐστί τε καὶ λέγεται "For the tongue is said to be, and is, a judge of what is sweet or bitter or sour")