7.
The Discourse on What Is Difficult to Practise
17.
"Difficult to practise and difficult to endure is the ascetic life for the inexperienced.
For many are the obstructions therein, in which the fool founders."
"How many days can one practise the ascetic life, if one dos not restrain the mind?
One would founder with each step under the control of one’s thoughts."
[The Blessed One:] "As a tortoise draws its limbs into its shell,
So a monk, drawing in the thoughts of his mind,
Independent, not harming others,
Fully quenched, would not blame anyone."