http://www.abuddhistlibrary.com/Buddhism/C%20-%20Zen/Sutras/The%20Shurangama%20Sutra/Shurangama%20Sutra.htm

The Dharma to Eliminate Deep-rooted Defilements
Ánanda put his palms together, bowed, and said to the Buddha,
"Having heard the Buddha’s unrestrained, greatly kind, true
and actual expression of Dharma that is pure in nature and
wonderfully eternal, I still have not understood the sequence for
releasing the knots so that when the six are untied, the one is
gone also. I only hope you will be compassionate, and once again
empathize with this assembly and those of the future, by offering
us explanation of the Dharma to wash and rinse away our deep-rooted
defilements."
Then, upon the lion’s throne, the Thus Come One
straightened his Nirvana robes, arranged his samghati sash, took
hold of the table inlaid with the seven gems, reached out onto the
table and picked up an exquisitely beautiful cloth given him by a
god from the Suyama Heaven.
Then, as the assembly watched, he tied it into a knot and
showed it to Ánanda, asking, "What is this called?"
Ánanda and the great assembly answered together, "It is
called a knot."
Then the Thus Come One tied another knot in the beautiful
cloth and asked Ánanda again, "What is this called?"
Ánanda and the great assembly once again answered
together, "It, too, is called a knot."
He continued in this pattern until he had tied six
knots in the beautiful cloth. As he made each knot, he held it up
to Ánanda and asked, "What is this called?"
That is also what happens when the six sense organs are freed:
even the one is gone. Because from beginning-less time your
mind and nature have been insane and disturbed, you have created
false knowledge and views. As that falseness continues to arise
without respite, perception becomes weary and defilements
arise. Just like the whirling flowers that appeared when the
eyes grew tired of staring, these too are disturbances that arise
without a cause within the tranquil, essential
brightness. Everything in the world—the mountains, the rivers,
the earth itself, as well as birth, death, and Nirvana—is these
flowers that appear because of our being turned upside-down by
insanity and weariness."