The Twin Verses (Yamaka Vagga) from the Dhammapada

All states are preceded by the mind, governed by the mind, and made by the mind. If one speaks or acts with a defiled mind, then suffering follows him as surely as the wheel follows the foot of the ox.

All states are preceded by the mind, governed by the mind, and made by the mind. If one speaks or acts with a serene mind, then happiness follows him like a shadow that never departs.

“He abused me, he struck me, he defeated me, he robbed me”—in those who harbour such thoughts, hatred is never appeased.

“He abused me, he struck me, he defeated me, he robbed me”—in those who do not harbour such thoughts, hatred is peacefully appeased.

For in this world hatred is never appeased by hatred; it is appeased only by freedom from hatred. This is the eternal law.

Those who do not realize that we are all subject to death continue their quarrels. But those who understand this truth settle their disputes.

One who dwells on the pleasant, with senses unrestrained, immoderate in eating, lazy and lacking effort — Mara overcomes such a person, as the wind overcomes a weak tree.

One who dwells on the unpleasant, with senses well restrained, moderate in eating, faithful and diligent — Mara cannot overcome such a person, as the wind cannot shake a mountain.

Whoever, not free from defilements, puts on the yellow robe, lacking self-control and truthfulness — that person is not worthy of the robe.

But whoever has discarded defilements, is well-established in virtue, and endowed with self-control and truthfulness — that person is truly worthy of the robe.

Those who mistake the worthless for the essential and the essential for the worthless, dwelling in wrong thoughts, never reach the essential.

But those who know the essential as essential and the worthless as worthless, dwelling in right thoughts, do reach the essential.

Just as rain penetrates a poorly thatched house, so passion penetrates an undeveloped mind.

Just as rain does not penetrate a well-thatched house, so passion does not penetrate a well-developed mind.

Here he grieves, hereafter he grieves; the evil-doer grieves in both worlds. He grieves and is afflicted, seeing the impurity of his own deeds.

Here he rejoices, hereafter he rejoices; the doer of good rejoices in both worlds. He rejoices and exults, seeing the purity of his own deeds.

Here he suffers, hereafter he suffers; the evil-doer suffers in both worlds. "Evil have I done," thus he suffers; he suffers even more when gone to a woeful state.

Here he delights, hereafter he delights; the doer of good delights in both worlds. "Good have I done," thus he delights; he delights even more when gone to a blissful state.

Though he recites much scripture, if he is heedless and does not act accordingly, he is like a cowherd counting others' cattle — he does not partake of the blessings of the holy life.

Though he recites little scripture, if he lives in accordance with the Dhamma, abandoning passion, hatred, and delusion, with full understanding and a well-liberated mind, clinging to nothing here or hereafter — he indeed partakes of the blessings of the holy life.