These are the four kinds of Clinging!
This
Noble 8-fold
Way is to be developed for the direct experience of the
four kinds of clinging, for the full understanding
of these types of clinging,
for their complete elimination, and for
their final overcoming,
abandoning
and leaving all behind...
The
Noble 8-fold
Way is
to be
developed for the ceasing of all
clinging!

Comment:
1: The
1st kind of clinging
to sights, sounds, smells, flavours, touches, and
thoughts is fairly obvious, yet still long habituated and thus tenacious...
2:
Clinging is to Views is
thinking: Doing good deeds are completely useless.
Doing evil has no consequences! No action has any effect on my future!
3:
Clinging to rituals & superstition
is like thinking that fire, bathing, and
various empty rituals, like wearing funny hats & praying, can purify mind...
3:
Clinging to an Ego-concept,
personality-belief, & a 'self' is the assuming
an unchanging internal entity 'I-Me', which however is non-existent...
The proximate cause of all
clinging is Craving, which has to be left!
This is the 2nd Noble Truth!
Clinging means:
adhering, attaching, gripping,
clasping, clutching, and grasping, to
which we stick stubbornly and tenaciously.
The word pali word The Buddha used
'Upādāna' literally
means 'taking up'
indicating that, as soon as one takes up the object, then clinging occurs!


Sariputta once
said:
When, friends, a Noble Disciple understands clinging,
the cause of clinging,
the ceasing of
clinging,
and the way leading to the ceasing of
clinging, in
that way he is one of right
view,
whose view is straight,
who has perfect
confidence in the Dhamma, and has arrived at this true Dhamma...
And what is clinging,
what is the cause of clinging, what is the
ceasing of
clinging, what is the way to
the cease clinging?
Friends: There are these 4 kinds of
clinging: clinging
to sense-pleasures,
clinging to views,
clinging to rituals
& superstition, and the subtle clinging
to the ego-concept
of an assumed inner self. With the arising of craving,
clinging
also arises.
With the ceasing of craving, clinging thus ceases too!
The way leading to the ceasing of clinging
is just this
Noble 8-fold Way:
Right View,
Right,
Motivation,
Right
Speech,
Right
Action,
Right Livelihood,
Right
Effort,
Right Awareness, and
Right Concentration...
Source:
Majjhima Nikāya 9.
Sammaditthi Sutta: Discourse on Right View
http://www.accesstoinsight.org/canon/sutta/majjhima/mn-009-nb0.html

More on Clinging
(Upādanā):
An intensified quite painful form of craving.
What are the 5 Clusters of Clinging,
Cool Calm,
Stilling_of_Clinging,
The_Terror_of_Being,
Without_Possessions,
Shaking_off_Evil,
Clinging_to_the_notion_I_Am,
Quenched,
Without_Clinging!

Good Dhamma talk by Ven. Thanissaro Bhikkhu on Clinging:
http://dhammatalks.org/Archive/061023%20Feeding%20Frenzy!%20Dependent%20Co-arising.mp3
Source (edited extract):
The Grouped Sayings of the Buddha.
Samyutta Nikāya.
Book [V:59]
section 45: The Way. 173: The 4 Clingings ...
http://store.pariyatti.org/Connected-Discourses-of-the-Buddha_p_1379.html
https://What-Buddha-Said.net/library/ati_website/html/tipitaka/sn/index.html.