4.
The Discourse on the Mental Knots
175.
"Monks, there are these four mental knots.
Which four?
Covetousness is a (mental) body knot, anger is a (mental) body knot, adherence to moral rules and austerities is a (mental) body knot, dogmatic belief that 'This alone is the truth' is a (mental) body knot -
these, monks, are the four mental knots.
For the direct knowledge, full understanding, utter elimination, and abandoning of these four mental knots, monks, etc.
this noble eightfold path is to be developed."
The fourth.