SN35.240 — Kummopamasutta
Once upon a time a tortoise was foraging for food on the riverbank in the evening.
A jackal was also foraging for food on the riverbank in the evening.
The tortoise saw the jackal from a distance while foraging.
Seeing this, it withdrew its limbs into its shell and remained silent and still.
The jackal saw the tortoise from a distance while foraging.
Seeing this, it approached the tortoise and stood nearby, thinking, If this tortoise extends any of its limbs, I will seize it, pull it out, and eat it.
However, as long as the tortoise did not extend any of its limbs, the jackal, unable to find an opening, eventually left.
In the same way Māra the Evil One is always waiting for an opportunity, thinking, Perhaps I might find an opening in their eyes... or in their ears... or in their nose... or in their tongue... or in their body... or in their mind.
Therefore live with your sense faculties guarded.
When seeing a form with the eye, do not grasp its signs and features.
If you leave the eye faculty unguarded, evil unwholesome states of longing and dejection might invade you. Practice restraint for its protection, guard the eye faculty, and undertake its restraint.
When hearing a sound with the ear...
When smelling an odor with the nose...
When tasting a flavor with the tongue...
When touching a tangible with the body...
When cognizing a mental phenomenon with the mind, do not grasp its signs and features.
If you leave the mind faculty unguarded, evil unwholesome states of longing and dejection might invade you. Practice restraint for its protection, guard the mind faculty, and undertake its restraint.
When you live with your sense faculties guarded, Māra the Evil One, finding no opening, will become disheartened and leave, just as the jackal left the tortoise.
Like the tortoise withdrawing its limbs into its shell, the disciple withdraws his thoughts into his mind.
Anissito, not depending on another,
One who has attained final Nibbana would not blame anyone.