Cetanaham Bhikkhave kamman vadami.

Bhikkhus, I say that kamma is intention.

According to the Theravada Buddhist tradition, before we may attain a full understanding of advanced topics such as rebirth and nibbana, first, as a foundation, we need to clear and clean house, both bodily and mentally, by cultivating moral purity in the practice of everyday morality (sila).

Before we commit any act, either mentally or physically, we should be capable of discerning whether the intention leading to the performance of the action springs from good or bad intentions.

Mind is forerunner all conditions . . . conditions are mind made.
If one speaks or acts with a wicked mind . . . pain follows.
If one speaks or acts with a good mind . . . happiness follows.

Right Concentration, quite literally, means firm intent, and if we intend to enjoy positive results on the path, we need to concentrate upon:

Cultivating good intentions and actions;
Cutting out bad intentions and actions.

On one hand

Good actions/deeds will result in good results/consequences, for example:

There are 10 kinds of wholesome moral intentions/actions which lead to beneficial results, they are:

Generosity (dana)
Morality (sila)
Meditation (bhavana)
Reverence (apacayana)
Service (veyyavacca)
Transference of merit (pattidana)
Rejoicing in others' merit (anumodana)
Hearing the doctrine (dhammasavana)
Expounding the doctrine (dhammadesana)
Forming correct views (ditthijjukamma)

Wholesome actions become the root causes of resultant good effects, for example:

Generosity yields wealth;
Morality causes one to be born in noble families in states of happiness;
Meditation gives birth in planes of form and formless planes, and helps to gain higher knowledge and emancipation;
Reverence is the cause of noble parentage;
Service is the cause of a large retinue;
Transference of merit causes one to be able to give generously in future rebirths;
Rejoicing in the merit of others is productive of joy wherever one is born;
Both hearing and expounding the doctrine are conducive to wisdom.

Wholesome roots and causes yield wholesome effects, and this should not be difficult for the devotee to understand. 

Whereas, on the other hand

Unwholesome roots will yield unwholesome fruits. To explain further:

Immoral kamma is rooted in greed (lobha), anger (dosa), and delusion (moha). These kinds of actions must be rooted out because they are dangerous for our mental health and development, so this is where we have to concentrate with aroused energy and due diligence.

There are 10 kinds of immoral actions which lead to unbeneficial, undesirable, and harmful results. For example:

Killing, stealing, and unchastity are caused by deeds;
Lying, slandering, harsh language, and frivolous talk are caused by words;
Covetousness, ill-will, and false view are caused by thoughts.

Of these 10, killing means the destruction of any living being, including animals and creatures of all kinds. To commit the offense of killing, five conditions are necessary, namely: a being, having consciousness that it is a being, having the intention of killing, effort, and consequent death. The evil effects of killing are: short life, being prone to disease, feeling constant grief caused by separation from loved ones, and constant fear.

To commit the offense of stealing, five conditions are necessary, namely: the property of other people, consciousness that it is so, having the intention of stealing, effort and resultant removal. The effects of stealing are: poverty, wretchedness, unsatisfied desires, and dependent livelihood.

To commit the offense of unchastity or sexual misconduct, three conditions are necessary, namely: the intention to enjoy the forbidden object, effort, and possession of the desired target. The effects of unchastity are: having many enemies, having undesirable wives, being born as a woman, or born as a eunuch.

To commit the offense of lying, four conditions are necessary, namely: untruth, the intention to deceive, effort, and communication of the matter to others. The effects of lying are: being tormented by abusive speech, being subject to vilification, incredibility, and stinking mouth.

To commit the offense of slandering, four conditions are necessary, namely: division of persons, the intention to separate them, effort, and communication. The effect of slandering is the dissolution of friendship without any sufficient cause.

To commit the offense of using harsh language, three conditions are necessary, namely: someone to be abused, angry thought, and use of abusive language. The effects of harsh language are: being detested by others although blameless and having a harsh voice.

To commit the offense of frivolous talk, two conditions are necessary, namely: the inclination toward frivolous talk and its narration. The effects of frivolous talk are: disorders within bodily organs and unacceptable speech.

To commit the offense of covetousness, greed, and avarice (abijjha), two conditions are necessary, namely: coveting another’s property and having a strong desire for it, saying, “Would that this property were mine.” The effect of covetousness is unfulfillment of one’s wishes.

To commit the offense of ill-will (vyapada), two conditions are necessary, namely: another being and the intention of doing harm. The effects of ill-will are: ugliness, various diseases, and a detestable nature.

Committing the offense of false view (micchaditthi) means seeing things wrongly, without being able to understand what they are truly. To complete this false view, two conditions are necessary, namely: the perverted way in which an object is viewed and the misunderstanding of it according to that wrong view. The effects of false view are: base attachment, lack of wisdom, dull wit, chronic disease, and blameworthy ideas.

As long as we are feeling mentally unsettled due to the consequences of our  unwholesome, immoral actions, we will not yet have developed the mental stability or the peace of mind to be able to cultivate the skills in concentration necessary for reaching higher states of mental purity.

According to the law of kamma, we must:

Bear the moral consequences of our bad intentions;
Benefit from the consequences of our good intentions.

We are the owners and heirs of our kamma, and, fortunately, we are able to influence the direction in which our kamma leads, dependent upon whether we are acting based respectively on good intentions or acting based on bad intentions.

See more

Essential Themes Of Buddhists Lectures (BuddhaSassana)
Ten Immoral Actions (Dasa Akusala) (Pure Dhamma)

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