From the Dhammapada, verse 35:
“A disciplined mind brings happiness.” The Buddha
This is a canonical quote, and it’s rather lovely. It’s from the Samyutta Nikaya, and in Bhikkhu Bodhi’s translation you’ll find it on page 708:
“Therefore, bhikkhus, you should train yourselves thus: ‘We will develop and cultivate the liberation of mind by lovingkindness, make it our vehicle, make it our basis, stabilize it, exercise ourselves in it, and fully perfect it.’ Thus should you train yourselves.”
This is a genuine quote from the Buddhist scriptures. It’s from the Karaniya Metta Sutta:
“Radiate boundless love towards the entire world.” Buddha
This is a saying from the Pali canon, upadhi dukkhassa mūlanti, which means “Attachment is the root of suffering.” So this is a genuine canonical quote.
You’ll find it in this sutta, but translated by Thanissaro as “Acquisition is the root of stress.” His translations are rather idiosyncratic.
In this translation of the same sutta it’s “acquisition is the root of suffering.”
Bhikkhu Bodhi’s translation (not available online, but in The Middle Length Discourses of the Buddha, page 868) has “attachment is the root of suffering,” although he sometimes has “acquisition” in place of “attachment,” in various repetitions of the phrase.
“The calmed say that what is well-spoken is best;
second, that one should say what is right, not unrighteous;
third, what’s pleasing, not displeasing;
fourth, what is true, not false.” – The Buddha
(From the Sutta Nipata)
This is a genuine Buddha quote. It’s from verse 76 of the Dhammapada. Here’s a link to an alternative translation.
“Should you find a wise critic to point out your faults, follow him as you would a guide to hidden treasure.” Buddha
“If a man going down into a river, swollen and swiftly flowing, is carried away by the current — how can he help others across?” – The Buddha
(From the Sutta Nipata)
This striking verse is found in the Magandiya Suta in the Sutta Nipata, which is generally held to be one of the oldest texts in the Pali canon.
Bhikkhu Thanissaro translates this as:
“Those who grasp at perceptions and views
go about butting their heads in the world.”
Fausböll, a 19th century pioneer translator, has:
“But those who grasped after marks and philosophical views, they wander about in the world annoying people.”
“Those attached to the notion ‘I am’ and to views
Roam the world offending people.”
The translator notes that “I am” is not in the quotation, but that its inclusion is warranted by material nearby.
The original Pali is:
Saññaca diṭṭhiñca ye aggahesuṃ
Te ghaṭṭayantā vicaranti loketi.
My rendition would be:
Those who cling to perceptions (saññā) and views (diṭṭhi)
Wander (vicarati) the world offending (ghaṭṭeti) people.
[Added later: Bhikkhu Varado’s translation, which I just discovered, is almost identical to mine: “Those attached to perception and views / roam the world offending people.”]