The Buddha describes the barrier of ignorance as the most significant obstruction, by which beings continue wandering on in cyclic existence.
Vuttañhetaṁ bhagavatā vuttamarahatāti me sutaṁ:
This was said by the Blessed One, said by the Arahant, as I have heard:
“Nāhaṁ, bhikkhave, aññaṁ ekanīvaraṇampi samanupassāmi yena nīvaraṇena nivutā pajā dīgharattaṁ sandhāvanti saṁsaranti yathayidaṁ, bhikkhave, avijjānīvaraṇaṁ. Avijjānīvaraṇena hi, bhikkhave, nivutā pajā dīgharattaṁ sandhāvanti saṁsarantī”ti.
“Bhikkhus, I do not see any other single barrier, obstructed by which, beings have wandered on and undergone |repeated existence::wandering on from one state of existence to another, the cycle of birth and death, moving on continuously [saṁsāra]| for a long time, like this barrier of |ignorance::fundamental unawareness or misunderstanding of the true nature of reality, not experientially understanding the four noble truths [avijjā]|. Indeed, bhikkhus, it is because beings are obstructed by the barrier of ignorance that they have wandered on and undergone repeated existence for a long time.”
Etamatthaṁ bhagavā avoca. Tatthetaṁ iti vuccati:
The Blessed One spoke on this matter. In this regard, it is said:
“Natthañño ekadhammopi,
yenevaṁ nivutā pajā;
Saṁsaranti ahorattaṁ,
yathā mohena āvutā.
“There is no other single thing,
surrounded by which, beings,
wander on day and night,
as when surrounded by |illusion::delusion, erroneous belief, false idea, misapprehension; it fuels further confusion and doubt [moha]|.
Ye ca mohaṁ pahantvāna,
tamokhandhaṁ padālayuṁ;
Na te puna saṁsaranti,
hetu tesaṁ na vijjatī”ti.
But those who have put an end to illusion,
and have shattered the mountain of ignorance;
They do not undergo repeated existence,
for the cause no longer exists for them.”
Ayampi attho vutto bhagavatā, iti me sutanti.
This matter too was spoken by the Blessed One, as I have heard.
This was said by the Blessed One, said by the Arahant, as I have heard:
“Bhikkhus, I do not see any other single barrier, obstructed by which, beings have wandered on and undergone |repeated existence::wandering on from one state of existence to another, the cycle of birth and death, moving on continuously [saṁsāra]| for a long time, like this barrier of |ignorance::fundamental unawareness or misunderstanding of the true nature of reality, not experientially understanding the four noble truths [avijjā]|. Indeed, bhikkhus, it is because beings are obstructed by the barrier of ignorance that they have wandered on and undergone repeated existence for a long time.”
The Blessed One spoke on this matter. In this regard, it is said:
“There is no other single thing,
surrounded by which, beings,
wander on day and night,
as when surrounded by |illusion::delusion, erroneous belief, false idea, misapprehension; it fuels further confusion and doubt [moha]|.
But those who have put an end to illusion,
and have shattered the mountain of ignorance;
They do not undergo repeated existence,
for the cause no longer exists for them.”
This matter too was spoken by the Blessed One, as I have heard.
Vuttañhetaṁ bhagavatā vuttamarahatāti me sutaṁ:
“Nāhaṁ, bhikkhave, aññaṁ ekanīvaraṇampi samanupassāmi yena nīvaraṇena nivutā pajā dīgharattaṁ sandhāvanti saṁsaranti yathayidaṁ, bhikkhave, avijjānīvaraṇaṁ. Avijjānīvaraṇena hi, bhikkhave, nivutā pajā dīgharattaṁ sandhāvanti saṁsarantī”ti.
Etamatthaṁ bhagavā avoca. Tatthetaṁ iti vuccati:
“Natthañño ekadhammopi,
yenevaṁ nivutā pajā;
Saṁsaranti ahorattaṁ,
yathā mohena āvutā.
Ye ca mohaṁ pahantvāna,
tamokhandhaṁ padālayuṁ;
Na te puna saṁsaranti,
hetu tesaṁ na vijjatī”ti.
Ayampi attho vutto bhagavatā, iti me sutanti.