St. John Climacus
“Someone who had asked me once about stillness told me that talkativeness invariably results from one of the following causes: from a bad or relaxed life-style (‘the tongue,’ he said, ‘is a member of the body, like the rest, and therefore needs to be trained in its habits’); or it comes from vainglory, a particular problem with ascetics; or it comes at times from gluttony, which is why many who keep a hard check on the stomach can more easily restrain the blathering tongue.”
Source: St. John Climacus, The Ladder of Divine Ascent