Cultivation of the four jhānas slants, slopes, and inclines one towards Nibbāna
At Sāvatthi.
There the Blessed One said:
"Bhikkhus, there are these four jhānas. What four?
Here, bhikkhus, a bhikkhu, quite secluded from sensual pleasures and unwholesome mental states, with reflection and examination (of thoughts), born of seclusion, filled with joyful pleasure, enters and dwells in the first jhāna.
With the subsiding of reflection and examination (of thoughts), experiencing internal tranquility and unification of mind, devoid of reflection and examination, born of collectedness and filled with joyful pleasure, he enters and dwells in the second jhāna.
With the fading away of joyful pleasure, he dwells equanimous and mindful, fully aware, and experiences physical pleasure, which the Noble Ones describe as 'one who dwells happily, equanimous and mindful.' Thus, he enters and dwells in the third jhāna.
With the abandoning of ease (bliss) and suffering (discontentment, stress), and with the previous disappearance of joy and sorrow, experiencing neither painful nor pleasant sensation, and with the purity of equanimity and mindfulness, he enters and dwells in the fourth jhāna.
These, bhikkhus, are the four jhānas.
Just as the river Ganges slants, slopes, and inclines towards the east, so too, bhikkhus, a bhikkhu who develops and cultivates the four jhānas slants, slopes, and inclines towards Nibbāna.
And how, bhikkhus, does a bhikkhu who develops and cultivates the four jhānas slant, slope, and incline towards Nibbāna?
Here, bhikkhus, a bhikkhu, quite secluded from sensual pleasures and unwholesome mental states, with reflection and examination (of thoughts), born of seclusion, filled with joyful pleasure, enters and dwells in the first jhāna.
With the subsiding of reflection and examination (of thoughts), experiencing internal tranquility and unification of mind, devoid of reflection and examination, born of collectedness and filled with joyful pleasure, he enters and dwells in the second jhāna.
With the fading away of joyful pleasure, he dwells equanimous and mindful, fully aware, and experiences physical pleasure, which the Noble Ones describe as 'one who dwells happily, equanimous and mindful.' Thus, he enters and dwells in the third jhāna.
With the abandoning of ease (bliss) and suffering (discontentment, stress), and with the previous disappearance of joy and sorrow, experiencing neither painful nor pleasant sensation, and with the purity of equanimity and mindfulness, he enters and dwells in the fourth jhāna.
Thus, bhikkhus, a bhikkhu who develops and cultivates the four jhānas slants, slopes, and inclines towards Nibbāna."
As the stones in this picture throttle the natural flow of the stream of water, likewise, the mental hindrances when present, throttle the flow of the clear experience of the unconditioned enlighten-mental quality of joy. Having cleared the mental hindrances through a well established life practice, one is then naturally able to dwell in the jhānas. One who develops and cultivates the jhānas, slants, slopes and inclines towards Nibbāna.
Related Teachings:
The five hindrances weaken wisdom | simile of side-channels weakening a river's flow (AN 5.51) - The five hindrances weaken wisdom like side-channels weaken a river’s flow.
Thoughts arise from a cause, not without a cause (SN 14.12) - In this teaching, the Buddha is sharing that as one grows in mindfulness, one is able to have a greater choice in recognizing which thoughts are arising and if they're in the unwholesome category, then one is able to apply right effort and abandon them. If they're in the wholesome category, then one is able to apply right effort to sustain and cultivate them.
Six Qualities to Abandon To Dwell in the first jhāna (AN 6.73)