Obstacles
Āvaraṇa Sutta  (AN 5:51)

On one occasion the Blessed One was staying near Sāvatthī in Jeta’s Grove, Anāthapiṇḍika’s monastery. There he addressed the monks, “Monks!”

“Yes, lord,” the monks responded to him.

The Blessed One said: “These five are obstacles, hindrances that overwhelm awareness and weaken discernment. Which five?

“Sensual desire is an obstacle, a hindrance that overwhelms awareness and weakens discernment. Ill will… Sloth & drowsiness… Restlessness & anxiety… Uncertainty is an obstacle, a hindrance that overwhelms awareness and weakens discernment. These are the five obstacles, hindrances that overwhelm awareness and weaken discernment. And when a monk has not abandoned these five obstacles, hindrances that overwhelm awareness and weaken discernment, when he is without strength and weak in discernment: For him to understand what is for his own benefit, to understand what is for the benefit of others, to understand what is for the benefit of both, to realize a superior human state, a truly noble distinction in knowledge & vision—that is impossible.

“Suppose there were a river, flowing down from the mountains—going far, its current swift, carrying everything with it—and a man would open channels leading away from it on both sides, so that the current in the middle of the river would be dispersed, diffused, & dissipated; it wouldn’t go far, its current wouldn’t be swift, and it wouldn’t carry everything with it. In the same way, when a monk has not abandoned these five obstacles, hindrances that overwhelm awareness and weaken discernment, when he is without strength and weak in discernment: For him to understand what is for his own benefit, to understand what is for the benefit of others, to understand what is for the benefit of both, to realize a superior human state, a truly noble distinction in knowledge & vision—that is impossible.

“Now, when a monk has abandoned these five obstacles, hindrances that overwhelm awareness and weaken discernment, when he is strong in discernment: For him to understand what is for his own benefit, to understand what is for the benefit of others, to understand what is for the benefit of both, to realize a superior human state, a truly noble distinction in knowledge & vision—that is possible.

“Suppose there were a river, flowing down from the mountains—going far, its current swift, carrying everything with it—and a man would close the channels leading away from it on both sides, so that the current in the middle of the river would be undispersed, undiffused, & undissipated; it would go far, its current swift, carrying everything with it. In the same way, when a monk has abandoned these five obstacles, hindrances that overwhelm awareness and weaken discernment, when he is strong in discernment: For him to understand what is for his own benefit, to understand what is for the benefit of others, to understand what is for the benefit of both, to realize a superior human state, a truly noble distinction in knowledge & vision—that is possible.”

See also: DN 2; SN 46:51; AN 4:96; AN 4:99; AN 9:64