मनु स्मृति - मनः पापः

परद्रव्येष्वभिध्यानं मनसानिष्टचिंतनम् |
वितथाभिनिवेशश्च त्रिविधं कर्म मानसम् ||

- मनु स्मृति

The following three are the sins committed by our mind (not our actions) - Longing for other people's treasures, thinking ill of others and having firm belief in the untruth.

- Manu Smriti

पंचतंत्र - काकोलूकीय - पण्डितः - सभा

परपरिवादः परिषदि न कथंचित्पण्डितेन वक्तव्यः |
सत्यमपि तन्न वाच्यं यदुक्तमसुखावहं भवति ||

- पंचतंत्र - काकोलूकीय

A wise man knows how to behave in a gathering. He knows well that he must not ridicule/talk harshly to any one (even when they are his opponents). Some times, even the truth must not be told. Especially when it is sure to hurt some one.

- Panchatantra - Kakolukiya

सुभाषितसुधानिधि - आपदः

परनिंदासु पाण्डित्यं स्वेषु कार्येष्वनुद्यमः |
प्रद्वेषश्च गुणज्ञेषु पंथानो ह्यापदां त्रयः ||

सुभाषितसुधानिधि

There are three ways one can invite trouble - by attaining mastery in criticizing others, by being lethargic in one's own work and by being an enemy of the virtuous.

- Subhashitasudhanidhi

हितोपदेश - मूर्ख - उपदेश

पायपानं भुजङ्गानां केवलं विषवर्धनम् |
उपदेशो हि मूर्खाणां प्रकोपाय न शान्तये ||

- हितोपदेश

If you give milk to a snake it will only result in more venom. Just like that advice given to a fool (in anger) will only increase his

- Hitopadesha

गरुडपुराण - परं तत्त्वं

पठन्ति वेदशास्त्राणि बोधयन्ति परस्परम् |
न जानन्ति परं तत्त्वं दर्वी पाकरसं यथा ||

- गरुडपुराण

They study the Vedas. Exchange notes and teach each other. Still they do not know the ultimate truth that is being discussed in the Vedas. Just like the serving spoon that never knows the taste of the dish.

- Garuda Purana

याज्ञवल्क्य - राजधर्म

प्रजापीडनसंतापात्समुद्भूतो हुताशनः |
राज्ञः कुलं श्रियं प्राणान् चादग्ध्वा न निवर्तते ||

- याज्ञवल्क्य

The heat from the hatred felt by the subjects will not relent until it burns down the king, his dynasty and his wealth. Such is the hatred that is caused by a king who builds his treasure by hurting his subjects.

- Yajnavalkya

अन्योक्तिस्तबक - कमल

पङ्कोद्भवं न च विमर्दसहं सदैव
    शैवालजालसहवासविडंबितं च |
इन्दीवरं दिनकरेण महाशयेन
    संभावितं भवति भाजनमिन्दिरायाः ||

- अन्योक्तिस्तबक

A lotus has its origin in slush. It is very gentle. It is easily hurt even by small force. It is subject to ridicule since it accompanies dirty algae all the time. But it is blessed by the Sun God. A lotus blooms when his rays fall over it. It becomes so beautiful and strong that Goddess Lakshmi sits on it. If you have blessings from a virtuous man, then it does help a lot.

- Anyoktistabaka

भामिनीविलास - गुणगौरव

नैर्गुण्यमेव साधीयो दिगस्तु गुणगौरवम् |
शाखिनोऽन्ये विराजन्ते खण्ड्यन्ते चन्दनद्रुमः ||

- भामिनीविलास

It is better not to have any virtues than dealing with lot of respect that virtue attracts. Look at the other trees in the forest that grow without any hindrances. It is only the sandalwood tree that gets cut down due to its superior quality

- Bhaminivilasa

मनु स्मृति - नित्य धर्म - सूर्य

नेक्षेतोद्यंतमादित्यं नास्तंयंतं कदाचन |
नोपसृष्टं न वारिस्थं न मध्यं नभसो गतम् ||

- मनु स्मृति

One must not look at the sun directly just when it is rising, or setting, or at noon (directly above one's head), or its reflection in the water. Each of these have their own reasons not to be watched with naked eyes.

- Manu Smriti

चंपूरामायण बालकाण्ड - महता

नूनं जनेन पुरुषे महति प्रयुक्तं
    अगः परं तदनुरूपफलं प्रसूते |
कृत्वा रघूद्वहगतेः क्षणमंतारायं
    यद्भार्गवः परगतेर्विहतिं प्रपेदे ||

- चंपूरामायण, बालकाण्ड

When a common man's actions impede the great undertakings of a noble man, then the common man will meet with befitting fate (as punishment). Look at what happened to Parashurama (one of the incarnations of Lord Vishnu who will be in that form ever without salvation) for having impeded Rama's mission on earth although it was only for a second. Parashurama is destined to be in this world (earth) for ever without ever returning to his original self (as Vishnu).

- Champuramayana, Balakanda

सुभाषित सुधानिधि - तृष्णा

निरानन्दा दारा व्यसनविमुखो बांधवजनो
  जडीभूतो मित्रं धनविरहशीर्णः परिजनः |
असन्तुष्टं चेतः कुलिशकठिनं जीवितमिदं
  विधिर्वामारंभस्तदपि च मनो वाञ्छति सुखम् ||

- सुभाषित सुधानिधि

This verse describes the state of a utterly hopeless situation of a man. Wife is not happy. Relatives have opted to look the other way (to escape the awkward situation of being forced to help him). Friends are not responding. Those well-wishers around him are all penniless. Mind is unsatisfied. Life is as hard as it gets. Fate is against him. Still the mind is still wanting all the pleasures of life. Even when faced with such great misery, a man does not understand that the root cause of all misery is greed and desire.

- Subhashitasudhanidhi

अभिज्ञानशाकुन्तला - राजधर्म

नियमयसि विमार्गप्रस्थितानात्तदंडः
    प्रशमयसि विवादं कल्पसे रक्षणाय |
अतनषु विभवेषु ज्ञातयः सन्तु नाम
    त्वयि तु परिसमाप्तं बन्धुकृत्यं प्रजानाम् ||

- अभिज्ञान शाकुन्तला

This verse describes how must a noble king behave. He must bring those who wander astray by punishing them. He must settle disputes among his subjects fairly. He must understand that many people will be willing to be his relatives/well-wishers when he has all the money. But he himself must behave as if all his subjects are his relatives. One must not favor any one subject more than the other.

- Abhijnana Shakuntala

सुभाषित सुधानिधि - मूर्ख

निर्धनश्चापि कामार्थी दरिद्रः कलहप्रियः |
मंदशास्त्रो विवादार्थी त्रिविधं मूर्खलक्षणम् ||

- सुभाषित सुधानिधि

There are three kinds of fools - one who has lot of desires in spite of being penniless, one who gets into fights (quarrels) in spite of being poor (and hence at a disadvantage), one who gets into a debate without having enough knowledge about the subject matter.

- Subhashitasudhanidhi

बृहत् पराशर स्मृति - सुशील

निर्धनत्वमसत्यत्वं विद्यायुक्तस्य कर्हिचित् |
अस्थानित्वमभाग्यत्वं न सुशीलस्य कर्हिचित् ||

- बृहत् पराशर स्मृति सुशील

You may find an educated person being poor or corrupt. But you will never see a man with great character suffering from either poverty or misfortune. This shows that education alone can not make a man rich or upright. It is one's character that determines his fortunes.

- Bruhat Parashara Smriti

महाभारत - वन

नित्यं क्रोधात्तपो रक्षेत् धर्मं रक्षेच्च मत्सरात् |
विद्यां मानापमानाभ्यामात्मानं तु प्रमादतः ||

- महाभारत, वन

At all times, one must protect his penance from anger, morality from jealousy, knowledge from emotions (reactions to praise or ridicule), one self from madness.

- Mahabharata, Vana

भामिनीविलास - कूप

नितरां नीचोस्मीति त्वं खेदं कूप मा कदापि कृथाः |
अत्यन्तसरसहृदयो यतः परेषां गुणग्रहिताऽसि ||

- भामिनीविलास

Oh dear well! Just because you are physically so low, don't feel bad. You are not without virtues. You are very soft/kind (moist) hearted and receive people well. A well gives out water to any one who drops down a rope.

- Bhaminivilasa

मनु स्मृति - नित्य धर्म

नास्तिक्यं वेदनिंदां च देवतानां च कुत्सनम् |
द्वेषं दंभं च मानं च क्रोधं तैक्ष्ण्यं च वर्जयेत् ||

- मनु स्मृति

One must stay away from atheism, slandering the Vedas, speaking ill of the Gods, enmity with any one, pride, displaying self-importance, anger and caustic nature.

- Manu Smriti

मनु स्मृति - नित्य धर्म

नारुंतुदः स्यादार्तोऽपि न परद्रोहकर्मधीः |
यथाऽस्योद्विजते वाचा नालोक्यां तामुदीरयेत् ||

- मनु स्मृति

One must not speak harshly to any one even when he is in misery himself. Even in one's mind he must not think about hurting others. One must not speak in a way that will be perceived by most as inappropriate (or against prevailing norms).

- Manu Smriti

मनु स्मृति - नित्य धर्म

नान्नमद्यादेकवासाः न नग्नः स्नानमाचरेत् |
न मूत्रं पथि कुर्वीत न भस्मनि न गोव्रजे ||

- मनु स्मृति

One must cover both his upper and lower body while eating. One must not take bath entirely naked. One must not urinate by the side of a path, or over ashes, or in a cattle shed. It is obvious why one must not urinate by the side of the path. Ashes and Cow-dung (cow-urine) are known to have other good uses. It should not be contaminated by human urine.

- Manu Smriti

अत्रि संहिता - माता

नास्ति वेदात् परं शास्रं नास्ति मातुः परो गुरुः |
नास्ति दानात् परं मित्रं इहलोके परत्र च ||

- अत्रि संहिता

There is no scripture better than the Vedas. One who studies them need not study anything else. There is no better teacher than one's own mother. There is no better friend than (the fruits of) charity. All these hold true in this world as well as in the other world (after life).

- Atri Samhita

विश्वगुणादर्श - दुर्जन

नाधीतेऽत्र जनो यदि कश्चिधीते शते सहस्रे वा |
दुस्तर्केषु श्राम्यति दूरीकुरुते श्रुतिस्मृतिसुतर्कान् ||

- विश्वगुणादर्श

In a place where people do not study (vedas and other scriptures), even if there exists one rogue among hundreds (at least thousands) then he will lead all of them away from dharma (the moral code of life) as depicted in the scriptures. He will use his contorted logic and convince everybody else that his way of adharma (against dharma) is right.

- Vishvagunadarsha

मनु स्मृति - वासः

नाधार्मिके वसेद्ग्रामे न व्याधिबहुले भृशं |
नैकः प्रपद्येताध्वानं न चिरं पर्वते वसेत् ||

- मनु स्मृति

One must not live in a village where people do not follow dharma. One must not live in a place where disease is wide spread. One must not undertake a long journey alone. One must not live for long on a mountain. Living on mountain can take a toll on one's health

-Manu Smriti

मनुस्मृति - धर्म

नाऽधर्मश्चरितो लोके सद्यः फलति गौरिव ।
शनैरावर्तमानस्तु कर्तुर्मूलानि कृंतति ॥

- मनुस्मृति

The results of the deeds of cruelty (against dharma the code of life) are not immediately apparent unlike the benefits of domesticating a cow (you get milk on day one). Slowly the effects of mis-deeds surround the doer and cut the very roots of the source. Perpetrating cruelty will always end in the destruction of the culprit.

- Manu Smriti

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Update: Thanks Gayathri for pointing out the typo.

बृहत् पराशर स्मृति - वर

नातिदूरे न चासन्ने अत्याढ्ये चातिदुर्बले ।
वृत्तिहीने च मूर्खे च षट्सु कन्या न दीयते ॥

- बृहत् पराशर स्मृति

One must not give his daughter in marriage to a person who live in far off land, or very near you, or very strong (cause he could become oppressive soon), or very weak, or does not want to work or is an idiot.

- Bruhat Parashara Smriti

चारुचर्या - स्वामि धर्म

नात्यर्थमर्थार्थनया धीमानुद्वेजयेज्जनम् ।
अब्धिर्दत्ताश्वरत्नश्रीर्मथ्यमानोऽसृजद्विषम् ॥

- चारुचर्या

A wise man will not press his employees too much in order to earn a lot of profits. He will do just enough to keep them motivated. When the Gods and Demons churned the ocean, the ocean first gave the divine horse (ucchaishravas), the lot of gems, then Goddess Lakshmi. Still they continued to churn. Hence the ocean gave them poison (halaahala).

- Charucharya

PS: The real order of what the ocean offered during the churning is not accurate in the verse above. But it is only indicative of how a servant's response will be if he is demanded to work beyond reasonable times.

मनुस्मृति - नित्य धर्म

नाग्निं मुखेनोपधमेत् नग्नां नेक्षेत च स्त्रियम् ।
नामेध्यं प्रक्षिपेदग्नौ न च पादौ प्रतापयेत् ॥

- मनुस्मृति

This verse explains how to deal with fire. One must not blow at the fire directly from his mouth. There is always a risk of fire snarling back at you. Use a pipe to blow at fire. One must not look at naked ladies. One must not throw trash in the fire. It could cause various other chemical hazards. One must not stretch his legs towards the fire (to warm them). There is a danger of clothes catching fire. It is notable that the sages have talked about women along side fire.

- Manu Smriti

मनुस्मृति - नित्य धर्म

नाक्षैः क्रीडेत् कदाचित्तु स्वयं नोपानहौ हरेत् ।
शयनस्थो न भुंजीतेन न पाणिस्थं न चासने ॥

- मनुस्मृति

One must never play at the wheels (roulette). One must never hold his own foot wear in his hands - always wear it. Do not eat while on the bed. Do not eat holding the plate in one hand. Do not eat while sitting on a chair. Most of these may not be relevant to the way we live now. But, it only goes to show how Manu Smriti detailed out the way to live in that age.

- Manu Smriti

सुभाषितसुधानिधि - लोभ

न हि पूरयितुं शक्यः लोभः प्रीत्या कथंचन ।
नित्यगंभीरतोयाभिरापगाभिरिवाम्बुधिः ॥

- सुभाषितसुधानिधि

It is not possible to satiate desire by indulgence. All those big rivers may feed water into the ocean all year long - But can never fill up the ocean.

- Subhashitasudhanidhi

मनुस्मृति - धर्म - अधर्म

न सीदन्नपि धर्मेण मनोऽधर्मे निवेशयेत् ।
अधार्मिकाणां पापानं आशुपश्यन् विपर्ययम् ॥

- मनुस्मृति

One must not employ his mind in immoral activities even after he sees virtuous people having to suffer (shed tears) and rogues enjoying all the riches (and leading a luxurious life).

- Manu Smriti

दक्षस्मृति - मनस्

न स्थिरं क्षणमप्येकं उदकं तु यथोर्मिभिः ।
वाताहतं तथा चित्तं तस्मात्तस्य न विश्वसेत् ॥

- दक्षस्मृति

When there wind blowing the water does not stay still even for a second. Our mind is just like that. It will keep changing every second. Never trust it.

- Daksha Smriti