Nothing is more unsettling than talkativeness and more pernicious than an unbridled tongue, disruptive as it is of the soul’s proper state. For the soul’s chatter destroys what we build each day and scatters what we have laboriously gathered together.
We ought not to grieve or become irritated at anything because, by frequent vexation and irritability, we form the morally and physically very injurious habit of irritability, whilst by bearing opposition with equanimity we form the good and useful habit of enduring everything calmly and patiently.
A person lighting a fire first has a small piece of tinder. This represents the word of the brother who has upset him. This little fire is very feeble. What significance has the word of your brother? If you put up with it you blow out the small fire, but if you begin to think to yourself, 'Why did he say that to me? I myself can answer him. If he did not want to hurt me, he wouldn't have said that and believe me, I can upset him too.' In this case, you add small pieces of wood to the fire and some other fuel like the person that lights a fire and you produce smoke which is agitation. Agitation is the movement and coming together of thoughts which stimulate the heart and make it audacious. Audacity is the taking of retribution against the person that has upset you, and this becomes insolence as Abba Mark said, 'Evil accepted in thought makes the heart audacious, but when this is revoked through prayer and hope, it makes it contrite.'
In general, loquacity opens the doors of the soul, and the devout warmth of the heart at once escapes. Empty talk does the same, but even more so… Empty talk is the door to criticism and slander, the spreader of false rumors and opinions, the sower of discord and strife. It stifles the taste for mental work and almost always serves as a cover for the absence of sound knowledge…
Just as gold is found, washed out of a great amount of sand and it amounts to very small grains like millet, so also out of many human beings few will be approved. For those who seek the kingdom are clearly manifested, while those who merely wear its word as a beautiful ornament are the ones most conspicuous. For the same reason those are manifested who are seasoned with the heavenly salt and who speak out of the Spirit's treasures. The vessels appear in whom God is pleased and to whom He gives His grace. There are also others, who, with much patience, receive the sanctifying power in many different ways, as God wishes.
The candles burning on the altar represent the non-created Light of the Trinity, for the Lord dwells in an unapproachable light. They also represent the fire of Divinity which destroys our ungodliness and sins. The candles lit before the icons of the Savior signify that He is the True Light which lighteth every man that cometh into the world (John 1:9); at the same time, He is a Fire which engulfs and revives our souls and bodies.
You ask for some way of completely eradicating irritability. The inclination to irritability is given us to use against sin, and we were never meant to use it against our fellow men. When we do, we act contrary to our true nature.
The more a man's tongue flees verbosity, the more his intellect is illumined so as to be able to discern deep thoughts; for the rational intellect is befuddled by verbosity.
Think also of this: the person who is bound to earthly things may rejoice but may also be upset or disturbed or grieved over earthly things: his mind is exposed to continual changes. But the joy of your master (Matthew 25:21) is enduring, for God is unchangeable. Thus control your tongue at the same time as you discipline your body with fasting and strictness. Talkativeness is a great enemy of prayer. A spate of fluttering words stands in the way of the words of prayer. This is the reason that we shall render account for every careless word we utter (Matthew 12:36). One does not bring the dust of the road into a room that one wishes to keep clean; thus keep your heart free from gossip and chatter about the events of the day that is past.
The candles lit before the icons of the Theotokos are a symbol of the fact that She is the Mother of the Unapproachable Light, and also of Her most pure and burning love for God and Her love for mankind.
If Moses, who was a god to Pharaoh, was shut out from the Land of Promise because of one word, how much more will not the evil speech of our tongue, by which we offend and hurt both God and man, shut us out from heaven?