In most cases, "mouth" in the Bible represents thought and logic, especially the kind of active, concrete thought that is connected with speech. The reason for this is pretty obvious, but it also holds when people, for instance, remove a stone from the mouth of a well, which represents gaining access to spiritual ideas. The mouth is used for eating as well as speaking, of course. In those circumstances, it represents our first, most external perception of a new spiritual idea or desire. This also makes sense, mirroring the way tasting food in the mouth gives us an instant impression of the quality of the food.

5817. ‘Et fuit, cum ascendimus ad servum tuum patrem meum’: quod significet elevationem ad bonum spirituale, constat ex significatione ‘ascendere’ quod sit elevatio, de qua sequitur; et ex repraesentatione ‘Israelis’ qui hic est ‘pater’, quod sit bonum spirituale e naturali, de qua n. 4286, 4598. Elevatio quae per ‘ascendere’ significatur, est versus interiora, ut hic a veris in naturali quae repraesentantur per ‘decem’ filios Jacobi', ad bonum spirituale e naturali quod repraesentatur per ‘Israelem’; naturale enim est exterius et est interius, n. 5497, 5649; in naturali interiore est bonum spirituale quod ‘Israel’, et in naturali exteriore sunt vera Ecclesiae quae sunt ‘filii Jacobi’; inde per ‘ascendere ad patrem’ significatur elevatio ad bonum spirituale.