It means:
"I forgive from the bottom of my heart without any reservation) all living beings (who may have caused me any pain and suffering either in this life or previous lives), and I beg (again from the bottom of my heart without any reservation) for the forgiveness from all living beings (no matter how small or big) to whom I may have caused pain and suffering (in this life or previous lives) knowingly or unknowingly, mentally, verbally or physically (or if I have asked or encouraged someone else to carry out such activities).
Let all creatures know that I have a friendship with everybody and I have no revenge (animosity or enmity) toward anybody."
If we reflect back on ourselves we would realize that our mind is continuously busy either thinking on something which may be near to us or could even be as far away as the other end of the world, talking or doing physical activities. This thinking, our words or our physical activities would be reflection of our happiness, sorrow, anger, greed, jealousy, and egoism, etc. And, depending upon how we react to those, we attract various types of new karmas to our souls. No prudent person would like to attract impure karma and at certain stages any karma at all.
We know that, it is not as easy as turning off a light switch, but we have a choice to minimize the damage. We can reduce the influx and binding of impure karmas, so that things would be more conducive for our social and spiritual uplift which should ultimately lead to salvation or liberation from this worldly life of any kind.
Buzz word is "minimizing the damage to our soul".
The physical bondage of karmas can be loose (sithil), tight (gadha), tighter (nidhatta), and tightest (nikachit).
Nikachit- or tightest karmas are accumulated not only when our passions (anger, ego, deceit, and greed) are sever while carrying out our actions, but also if we don’t repent for our actions whenever we become aware of our impure action. These impure karmas obstruct Right Knowledge (Samyag Gnyan) and Right Action (Samyag Charitra) both are necessary ingredients to start the beginning of spiritual uplift which would ultimately lead to liberation.
As a human being we are able to recognize this factor better than other living beings. "Michchhami Dukkadam" can affect the type and nature of karmas bonding to our souls. The loose, tight bondage can easily be shed off by repenting and apologizing for our deeds which caused them. The moderate bondage can be shed off by austerity while sever bondage can be only shed off by suffering the results of those karmas.
When you say the mantra “Michchhami Dukkadam", first we become aware that we have or might have done some harms to others, and then when we regret and feel sorry for doing so, we also want to apologize for the same. So this repenting and expressing apology by saying “Michchhami Dukkadam" would help us to get rid of some of our karmas.
While we are trying to remove the impure karmas encrusted on our soul, we can do a little more contemplation and it would put us on a different path. One can do contemplation on:
1) Thinking of Friendship (Maitri Bhavana)
2) Thinking of Appreciation (Pramod Bhavana)
3) Thinking of Compassion (Karuna Bhavana)
4) Think of being neutral or uninvolved (Madhyastha Bhavana)
Let us understand how these bhavanas (State of Mind- attitude) play important roles in our lives, how they can keep us away from impure karmas, and ultimately how they can improve our overall chances to uplift our souls.
1. Thinking of Friendship (Maitri Bhavana)
All Saints have taught us, "We must be a friend to all living beings." The feeling of friendship brings love and respect for others. It also initiates a feeling of brotherhood among all, and in turn leaves no room for harm, deceit or quarrelsomeness with anybody. If we contemplate on Maitri Bhavana our thoughts, words, and actions will not be harsh, and we will not hurt anybody. On the contrary, we will support and protect everybody. Friendship will lead us to be tolerant, forgiving, and caring for one another. Therefore by developing a friendship with all living beings, we will avoid impure karma.
2. Thinking of Appreciation (Pramod Bhavana)
In this bhavana, we admire the success of our friends, spiritual leaders and enlightened-ones. One of the most destructive forces in our lives is jealousy. However, friendship combined with admiration, destroys jealousy. As jealousy subsides, negative impulses are turned into positive ones, and in time, you will be at peace.
3. Thinking of Compassion (Karuna Bhavana)
Instead of succeeding, many of our friends may be getting into trouble for things they should not be doing, and even those who are successful may be accumulating vices such as greed and ego. If such is the case then, they are not on the right path, and may be they are weak, helpless, and in distress. At a time like this, you should contemplate on the karuna bhavana and show compassion towards them, instead of being disgusted with them or hating them. Show them a right path with patience, tolerance, and forgiveness and offer them the needed support. In this way, not only will you be avoiding impure karma, but so will your friends.
4. Think of being neutral or uninvolved (Madhyastha Bhavana)
Life appears to be nothing but involvement. Sometimes life works out favorable and sometimes it does not. So when the things don’t workout, instead of getting disappointed, angry, or more involved, you should contemplate on madhyastha bhavana which leads to feeling that I did my best to resolve the situation. If someone does not want to understand, then leave him/her alone without getting further involved. You should simply hope that one of these days; he/she may understand and change.
By observing madhyastha bhavana, you will remain in equanimity, instead of provoking turmoil in your mind. When your mind stays neutral and uninvolved it keeps karma away.
In short, you can avoid influx of impure karma and stay in peace while living in worldly life by developing a friendship towards all living beings, admiring their success, holding their hands when they are in distress, and leaving them alone at times when they do not understand what is right or wrong.
So, until it becomes the natural way of your living, continue to observe the above bhavanas, and contemplate and practice "Michchhami Dukkadam", the magic mantra for healing yourself and others..