KATHOPNISHADA CHAPTER 6 SHLOKA - 15

                                                              यदा सर्वे प्रभिद्यन्ते

                                                             हृदयस्येह ग्रन्थयः । 

                                                            अथ मर्त्योऽमृतोभव-

                                                       -त्येतावद्ध्यनुशासनम् ॥ १5

                                               YADA  SARVE  PRABHIDYANTE

                                                RHYUDAYASYA GRANTHAYAH |

                                           ATHA  MARTYO AMRUTO BHAVANTI 

                                                  ETAVAT ANUSHASANAM ||15

                           WHEN  THE KNOTS OF THE  HEART  ARE SEVERED HERE ,

                       THE MORTAL BECOMES IMMORTAL AS  PER TEACHING ||15

      This Shloka is talking about practical part of MUKTI or freedom from the cycle of birth and death. The Shloka talks about KNOTTS . The knots are used to 'tie ' things up . We tie a rope to something so that it's not free and is attached. Let us say we tied a boat to a pole on shower - now the boat is not free . If the KNOT is not done properly the boat will float away. So the knots keep things together or attached or tied to things. So in this Shloka they are talking about breaking these knots . Say we tie a bot to the pole on the shower . The idea of tying the rope to the boat is that it's not free to float . It is tied down and if the knot is not done properly or comes loose then the boat will float away. The Knots in this Shloka they are they are talking about is are in the so called heart . These are described as AVIDYA - KAMA- KARMA .--IGNORANCE - DESIRES -- ACTIONS . The three are related to each other . The ignorance leads to desires  and desires lead to action. If we  know that eating high sugar food is not good if you have diabetes then we would not eat it . But the ignorance leads to desire to eat such food and then when we eat it which is action - it binds us . Remember the circle of mind - Action leads to impression-impression leads to desire and desire leads to action and the circle continues as the action leads to impression again. So here the three are related . 

  Some call these Knots as BRAHMA KNOT- RUDRA KNOT- VISHNU KNOT .The Brahma is the ignorance as he created the universe. The Rudra is the desire  and the Vishnu is the Karma or the Action. The Karma are also said to golden -if done with Satwic Guna - silver if done with Rajasic Guna  NS Iron if done with Tamasic Guna .Once we have released these Knots then we are not bound to this body and universe and we are free - that is what the we are told .