The Dhammapada 13 & 14

As a poorly covered house is penetrated by a rain, 

thus an undeveloped mind is penetrated by passion.

A roof is the most important part of any house. If the roof is not well done, if we try to "cheat" and use cheap material of poor quality, we can be surprised when a strong rain comes. The roof will not be able to hold off the water and it will leak. Everything inside the house then becomes wet instantly - and after the rain we can start building again.

 In the same way, the mind is the most important part of the human being. If it is not "well developed", if we have not practiced meditation earnestly, it will also "leak". The passions, hatred and other stuff will enter our mind and make it difficult for us to purify our minds. After one such "rain" we can start "rebuilding" our mind again.

As a well covered house is not penetrated by a rain, 

thus a well developed mind is not penetrated by passion.

And (continuing from DhP 13) if the roof on our house is well done, if we have made careful plans and executed them well, if we paid enough attention to the roof, then we do not have to be afraid of any rain, no matter how strong. The roof will hold it and the inside of the house will not become flooded, not even wet.

And in the case of mind, the same rule applies. If we made a conscious decision to develop it, to keep high level of mindfulness and alert, if we sharpen our mind in meditation, all the passions have no way of entering. The "roof" holds and we can concentrate on our main goal -- cleansing the mind, without a need to repair the roof after every light shower.

The Dhammapada - 11 & 12

Thinking to be essential, what is not, 

seeing no essence in what is essential, 

feeding on wrong thoughts, 

do not discover the essence.   

One can of course never expect to understand, or get close to, the "essence", the heart of the problem, if one keeps looking in the wrong direction. This is true in every field of our endeavor. Therefore this rule necessarily applies also to spiritual efforts. This verse says that if we mistake the essential things for nonsense and think that there is some essence in things that are actually empty of it, we cannot ever get even close to the reality. All kinds of superstition fall into this category, various activities that (although they look nice and can be even pleasant) do not bring us closer to the goal, which is the purification of mind. As the verse notes, this is the "pasture for wrong thoughts". As the cows on the pasture, the thoughts, wandering in this direction, will grow stronger and will multiply. The only problem is -- it will not help us on our way at all.

Having known the essence as the essence,

non-essential as non-essential, they,

feeding on right thoughts, discover the essence.

In contrast to DhP 11, if we really know, what is important and what is empty, if we know, where the essence lies, it is possible for us to discover it. We can take as an example the case if we want to clean the dirty floor. It will not help us to start scrubbing the table. Sure, a clean table is a nice thing, but we wanted the floor to be clean, not the table. In the same way, if we want to purify our mind, we must carefully decide and understand, how to do it, what is the correct procedure. If we know, what is essential in order to reach our goal, then we have a chance of accomplishing it. This is a "pasture for right thoughts". The right thoughts will grow and multiply -- this time only for our benefit.

The Dhammapada 9 & 10 

Who is not rid of defilement and will wear a yellow robe,

devoid of restraint and truth, 

he does not deserve a yellow robe.

This verse as well as the following one (DhP 10) talks about who is and who is not worthy to wear a monk's robe. One, who did not get rid of defilement (anikkasāvo), who is full of these impurities, who does notknow self-control and restraint (dama) and who is far away (apeto) from truth (sacca), does not deserve to wear a yellow robe. Such a person can not call himself a monk, even if he should be dressed in the monk's robe. 

A defilement (kasāva) is  usually understood to be the , three roots of evil: lobha (greed), dosa (hatred) and moha (delusion).

And who would get rid of defilement, well settled in virtues, 

Endowed with restraint and truth, he deserves a yellow robe.

In contrast to DhP 9, the person, who deserves to wear a monk's robe is described here. Who "threw up", or got completely rid of, defilement (vantakasāvo), who is well settled and well established in his virtues (sīlesu susamāhito) and who is endowed (upeto) with restraint (dama) and knows the truth (sacca), such a person deserves to wear a yellow monk's robe. Such a person can truly be called a monk.

The Dhammapada - 7 & 8

A person who lives contemplating on pleasant things,

who is not restrained in senses,

who does not know moderation in food,

who is indolent and of poor  effort,

Mara will overcome him,as wind a weak tree.

What is described here, is a recipe, how to become a prey of our own mind. For Mara, The Evil One, is not some outside force, some "devil" or deity of death and destruction, it is only our mind, our bad habits, laziness, evil intentions and especially ignorance, the true root of all evil. If we dwell with our minds only on the pleasant things, if we indulge in enjoying pleasurable things (subhānupassiṃ viharantaṃ), then it is easy for these tendencies in our brain ("Mara") to gain strength. The same thing happens, when we are unrestrained in six senses (eye, ear, nose, tongue, body and mind), taking in without restraint and reflection everything that comes and if we never have enough of sense pleasures (indriyesu asaṃvutaṃ). And of course, if we do not know moderation in food, we can expect the same result, because indulgence in food is actually a part of lack of restraint in senses (bhojanamhi cāmattaññuṃ). Laziness (kusītaṃ) and lack of effort to change our ways (hīnavīriyaṃ) will not help us to get rid of these bad habits and the roots of meditative life will slowly wither and die away. And without strong, often cultivated roots, the tree of our practice will not grow higher and higher, will never bring fruits in reaching the Nirvana, but our bad tendencies will subdue us, our hope for reaching the goal, just as easily, as wind uproots a weak tree.

The one, who does not live contemplating pleasant things,

who is well restrained in senses, 

Who does know moderation in food,

who is trusting and firm in effort, 

Mara will not overcome him, as wind a rocky mountain.

Here, on the other hand (in contrast to DhP 7) is described the way, how to nourish the roots of meditative life, how to destroy the bad tendencies, how to become immune to Mara, to the evil part of our mind. We must not dwell with our minds only on the pleasant things and indulge in enjoying pleasurable things (asubhānupassiṃ viharantaṃ). Another way to understand this phrase is that we should contemplate the unpleasant things, to understand that there is really nothing to be attached to, that attachment to pleasant things brings about the strength of "Mara", of our bad habits and tendencies. 

We must also be well restrained (indriyesu susaṃvutaṃ) in senses and know moderation in food (bhojanamhi ca mattaññuṃ). Thus, senses are guarded, we do not take everything in indiscriminately, and we contemplate on what we see, hear, smell, taste, touch and think. We are not attached to pleasant sense-impressions, we do not hate unpleasant sense-impressions, and we are observant and concentrated and thus able to bring meditation to everyday life. 

 Important part is also trust (saddhaṃ). Trust in the way, that the Buddha taught us, trust in the methods that are part of the way, trust in the goal that can be reached by following this way. Without this basic trust (which is not blind faith, for it is easily verified, as we go forward on the way) no progress is possible. 

We must also be firm in effort (āraddhavīriyaṃ). Effort is of course a basic necessity. We must make an effort to put everything that was said above into our daily lives. It is only by this constant effort, that we are able to progress towards the goal.

If we practice in this way, the roots of meditation will flourish, will become strong and invincible. Eventually, the tree of our practice will bear its fruit, our mind will reach the peaceful state of Nirvana. Mara, the dark side of our mind has no way to influence us, no way to overcome us, just like the wind is not able to blow away a rocky mountain.

The Dhammapada  5 & 6

“Hatred is indeed never appeased by hatred here. 
It is appeased by non-hatred - this law is eternal.”

This pair of verses (DhP 5 and 6) is very close in meaning to the previous pair (DhP 3 and 4). Again, a very simple truth, that most of the religions in the history have stressed again and again. The only cure for hatred is the abstention from it. Never can we stop people from hating us by hating them. In this way, mutual hatred will rise -- often to the point when hatred gives way to violence.

The only way to stop this chain of hatred is to stop hating, of course. As the verse says, this is an eternal law. It was always so and always will be. One can only wish that we could remember this verse in all situations and deal accordingly. How many wars, how much suffering could be easily averted just by taking the advice of this short verse seriously.

“The others do not understand that we should restrain ourselves here. 
Those who understand that, therefore appease their quarrels.”

This verse is related to the previous one (DhP 5), even if this relation is not apparent immediately. In DhP 5 we are told that hatred can not be appeased by hatred but only by abstention from hatred. Here it says that some people do not understand this, do not know that we should restrain ourselves, that we should not give in to hatred. Those who realize that, of course, stop their enmity and quarreling, thus stopping hatred completely.

By the word "others" the authors probably meant the people, who do not realize this eternal law (that hatred can be appeased by non-hatred only). The use of the word "here" ("that we should restrain ourselves here") suggests this world, our present situation. It can also point to the previous verse -- then we should understand "here" as "this" (meaning this eternal law of appeasing hatred by non-hatred).

The Dhammapada - 3 & 4

“He abused me, he beat me, 
He defeated me, he robbed me. 
Those, who harbour such thoughts, 
Their hatred is not appeased.”

This verse speaks about the very well known fact, so stressed by the modern psychology. If we succumb to thoughts of injustice done to us, if we always consider ourselves "poor things" that the "strong ones" play with, our suffering and hatred will never disappear, but it will increase, because "they" will feel our insecurity and will enjoy inflicting pain on us even more. "Oh, how could he (or she, for that matter) do this to me? It is so unfair!" By this thinking we will certainly not prevent these things to happen in the future again.

 How to deal with this situation is spoken about in the next verse.

“He abused me, he beat me, 
He defeated me, he robbed me. 
Those, who do not harbour such thoughts, 
Their hatred is appeased.”

This verse is a "twin verse" of the previous one. If we can not conquer the hatred and suffering by crying and feeling powerless, it is exactly by the absence of such thoughts, that our hatred will disappear and dissolve. And when those people who enjoy making us suffer, see that we are not intimidated and do not give in to their way of thinking, they will eventually stop this kind of behavior.

Indeed, it is said very easily and the majority of people will quickly agree with it, but it is extremely difficult to bring this idea to life. Therefore, we must practice this more often in our daily lives -- and our effort must bear its fruits.

All things are preceded by mind, 
Mind is their master, they are produced by mind. 
If somebody speaks or acts 
With a purified mind, 
Hence happiness follows him, 
Like never departing shadow.

This verse is closely related to the previous one . If the mind is purified, the mental phenomena it creates are also pure. Therefore, joy and happiness follow as surely as suffering and sorrow in case of a defiled mind. As we can see from these two verses, happiness and suffering depends on us entirely, on our own minds, on the thoughts that we are harboring. There is no other way to happiness then purification of mind and ultimately, in destroying all the defilement completely and reaching the highest goal, the awakenment or Nirvana.

All mental phenomena are preceded by mind, 
Mind is their master, they are produced by mind. 
If somebody speaks or acts 
With a corrupted mind, 
Hence suffering follows him, 
Like the wheel the foot of the bearing animal.

In this verse,  some philosophical observations are made about the nature of our mind. It says that all the mental phenomena, happiness or suffering, joy or sorrow are made by, or are the outcome of, the quality of the mind. These mental phenomena are (according to the teachings of Abhidhamma) feelings (vedanā), perception (saññā) and volitional activities (saṅkhāra). And because these phenomena are created by, or so closely related to, the mind, they are always "colored" in the same way as the mind is. If the mind (as in this verse) is corrupted, full of evil thoughts, then only suffering and sorrow awaits us as a result of this. In other words, the mind, creating these mental phenomena simply creates them "to its own image". Therefore, negative thinking always brings with it suffering and sorrow, just as the wheel follows in the path of the animal carrying the charriot. We experience suffering only because our minds are not purified, we are not awakened. To purify the mind is to get rid of suffering once and for all.