Mahakappinatthera Vatthu

得飲法（水）者，心清而安樂。智者常喜悅，聖者所說法。

Dhammapiti sukham seti
vippasannena cetasa
ariyappavedite dhamme
sada ramati pandito.

Drinking the Dhamma,
refreshed by the Dhamma,
one sleeps at ease
with clear awareness & calm.
In the Dhamma revealed
by the noble ones,
the wise person
always delights.

Uṣṇīṣa Vijaya Dhāraṇī Sūtra

namo bhagavate trailokya prativiśiṣṭaya buddhāya bhagavate.tadyathā, om, viśodhaya viśodhaya, asama-samasamantāvabhāsa-spharana gati gahana svabhāva viśuddhe,abhiṣiňcatu mām. sugata vara vacana amṛta abhiṣekai mahā mantra-padai.āhara āhara āyuh saṃ-dhāraṇi. śodhaya śodhaya gagana viśuddhe.uṣṇīṣa vijaya viśuddhe sahasra-raśmi sam-codite.sarva tathāgata avalokani ṣaṭ-pāramitā-paripūrani.sarva tathāgata mati daśa-bhūmi prati-ṣṭhite.sarva tathāgata hṛdaya adhiṣṭhānādhiṣṭhita mahā-mudre.vajra kāya sam-hatana viśuddhe.sarvāvaraṇa apāya-durgati pari viśuddhe, prati-nivartaya āyuh śuddhe.samaya adhiṣṭhite. maṇi maṇi mahā maṇi.tathatā bhūta-koṭi pariśuddhe. visphuṭa buddhi śuddhe.jaya jaya, vijaya vijaya. smara smara, sarva buddha adhiṣṭhita śuddhe,vajri vajragarbhe vajram bhavatu mama śarīram.sarva sattvānām ca kāya pari viśuddhe. sarva gati pariśuddhe.sarva tathāgata siñca me samāśvāsayantu.sarva tathāgata samāśvāsa adhiṣṭhite.budhya budhya, vibudhya vibudhya,bodhaya bodhaya, vibodhaya vibodhaya samanta pariśuddhe.sarva tathāgata hṛdaya adhiṣṭhānādhiṣṭhita mahā-mudre svāhā.

Uṣṇīṣa Vijaya heart-mantra:
oṃ amṛta-tejavati svāhā

"A Man of Virtue and Simplicity" recounted by Goenkaji - An Anecdote

My revered teacher [Sayagyi U Ba Khin] fully lived the ideals of Dhamma. He was a senior member of the civil service, where it was commonplace to amass fortunes through fraudulent practices. But Sayagyi was ripened in Dhamma. He worked in this corrupt environment and emerged without any stain on his character.

Sayagyi refused to accept even a penny from his students. Whenever we would offer him something after a course, he would call for the centre manager to insist that the donation go to the centre and a receipt be duly issued. He was equally scrupulous about accepting loans.

Bala Sutta: Fools (AN 2.98)

"Monks, these two are fools. Which two? The one who takes up a burden that hasn't fallen to him, and the one who doesn't take up a burden that has. These two are fools."

Annatarabhikkhu Vatthu

此心隨欲轉，Cǐ xīn suí yù zhuǎn,
輕躁難捉摸。qīng zào nán zhuōmō.
善哉心調伏，Shànzāi xīn diàofú, 
心調得安樂。xīn diào dé ānlè.

Dunniggahassa lahuno
yatthakamanipatino
cittassa damatho sadhu
cittam dantam sukhavaham.

The mind is difficult to control; swiftly and lightly, it moves and lands wherever it pleases. It is good to tame the mind, for a well-tamed mind brings happiness.

On Difficulties & Regrets

Student: Yesterday and today I've been sitting and saying, "This is too hard…".

S.N.Goenka: Dhamma is very easy and Dhamma is very hard. It can be both. It is very easy when you practise properly. When you don't practise properly it becomes very hard. So don't allow it to become very hard. Smilingly, make it easy, "I am not to do anything." It is easy not to do anything don't do anything. Let things happen. It is so easy. But when you try to do something, "I must do. I must stop this aversion. I must stop this craving." Then you create difficulty. Let things happen. You are just a silent witness of things happening. And it becomes so easy. Make it easy.

Happiness is an art - Thich Nhat Hanh

Whether this moment is happy or not depends on you. 
It's you that makes the moment happy. 
It's not the moment that makes you happy. 
With mindfulness, concentration and insight, any moment can become a happy moment.