The good of a well-directed mind (DhP 42, 43)

Whatever harm an enemy may do to an enemy,
or a hater to a hater,
an ill-directed mind inflicts on oneself a greater harm.

-- DhammaPada Verse 42

Neither mother, father, nor any other relative
can do one greater good
than one's own well-directed mind.

-- DhammaPada Verse 43

Related Teachings:

• Mind precedes all mental states (DhP 2) - If with a pure mind a person speaks or acts, happiness follows him like his never-departing shadow.
• Intention shapes all phenomena (From AN) ↗️ - Intention is kamma, by intending one creates kamma by way of body, speech and mind.
• The Mind of Loving-Kindness (MN 21) - Buddha's advice on cultivating a mind rid of ill-will with strong visual similes