Direct Path

Thus have I heard. On one occasion, the Buddha addressed a gathering of monks, "Friends," he began. "Venerable, Sir," they replied. And the Buddha said:

“Friends, this is a direct path that leads to the purification of hearts and minds, for the overcoming of unhealthy stress, depression and anxiety, for the transformation of suffering and discontentment, for attaining the noble path, for the realization of health, well-being, freedom, and awakening; specifically, the Four Foundations of Mindfulness.”

Definition

“What are the Four Foundations of Mindfulness? 

Here, friends, regarding the body: we abide, contemplating the body, diligent, clearly knowing, and mindful, free from desires and discontent concerning the world.

Regarding feelings: we abide, contemplating feelings, diligent, clearly knowing, and mindful, free from desires and discontent concerning the world. 

Regarding the mind: we abide contemplating the mind, diligent, clearly knowing, and mindful, free from desires and discontent concerning the world.

Regarding dhammas: we abide contemplating dhammas, diligent, clearly knowing, and mindful, free from desires and discontent concerning the world.”

[...]

Mindfulness of Breathing

“And how, friends, do we abide, contemplating the body?

• Here, having gone to the forest, or the root of a tree, or another peaceful and supportive location, we sit down; bringing ease and stability to the body, adopting an upright posture.
• We establish mindfulness in front of us, mindful as we breathe in, and mindful as we breathe out.
• Breathing in long, we know, 'the in-breath is long,' breathing out long, we know, 'the out-breath is long.' 
• Breathing in short, we know, 'the in-breath is short,' breathing out short, we know 'the out-breath is short.' 
• We train: 'I shall breathe in experiencing the whole body,' we train: 'I shall breathe out experiencing the whole body.' 
• We train: 'I shall breathe in, bringing calm to the body,' we train: 'I shall breathe out bringing calm to the body.'
  

Just as a skilled woodturner or their apprentice, when making a long turn, they know, 'The turn is long,' or when making a short turn, they know, 'The turn is short.' So too, breathing in long or short, we know, 'the breath is long, or short.”

Refrain

“In this way, regarding contemplating the body in the body,

• We abide contemplating the body internally, we abide contemplating the body externally, and we abide contemplating the body both internally and externally. 
• We abide contemplating the nature of arising in the body, we abide contemplating the nature of passing away in the body, and we abide contemplating the nature of both arising and passing away in the body. 
• And, mindfulness that 'there is a body' is established in us to the extent necessary for bare knowledge and continuous mindfulness. 
• And we abide independently, without clinging to anything in the world. 
  

That is how we abide, contemplating the body in the body.”

[...]

Prediction

"Friends, if we develop these four satipatthanas in such a way for seven years, one of two fruits could be expected for us:

1. Either we realize full awakening here and now,
2. Or, if there is a trace of clinging left, we enter 'never returning', having established the necessary conditions leading to full awakening.

Let alone seven years ... six years ... five years ... four years ... three years ... two years ... one year ... seven months ... six months ... five months ... four months ... three months ... two months ... one month ... half a month ... if we develop these four satipatthanas in such a way for seven days, one of two fruits could be expected for us:

1. Either realize full awakening here and now,
2. Or, if there is a trace of clinging left, enter 'never returning', having established the necessary conditions leading to full awakening.

And so, with reference to these things, it was said:

Direct Path

“Friends, this is a direct path that leads to the purification of hearts and minds, for the overcoming of unhealthy stress, depression and anxiety, for the transformation of suffering and discontentment, for attaining the noble path, for the realization of health, well-being, freedom, and awakening; specifically, the Four Foundations of Mindfulness.”

That is what the Buddha said. The monks were satisfied and delighted by his words.