Do not lend your ear to the tongue of the slanderer, nor your tongue to the ear of him who likes malicious talk, speaking or listening with enjoyment to words against one's neighbor. Cut yourself off from them, lest you fall away from love of God and find yourself exiled from eternal life.
A man standing on the seashore sees the immense expanse of water, but his eye can embrace only a small part and cannot reach its limit. In the same way, a man who, through contemplation, is given to see the limitless ocean of Divine glory and to see God Himself with the eyes of his mind, sees God and the infinite vastness of His glory, though not the whole as it really is, but only as much as is possible for him.
Grow calm, grow quiet after harmful noise... you will experience a certain movement towards eternity; gradually, like a still, small voice, a thought will come to you as to who you are and what is your end and purpose... this is a sign of the approach of the word of God in your soul.
Do not by any means allow yourself to open both ears to the slanderers and to draw your conclusions and decisions on the basis of what they alone have to say, and thereby judging the case in absentia without the presence of the person slandered to defend himself. Oftentimes many unjust and irrational decisions have followed from such slanderous accusations.
If you have spoken evil of your brother, and you are stricken with remorse, go and kneel down before him and say: 'I have spoken badly of you; let this be my surety that I will not spread this slander any further.' For detraction is death to the soul.
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.
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.
Unless the inner man meditates upon the law of God and is nourished thereby, unless he is strengthened by reading and by prayer, he is conquered by the outer man, and he serves his master.