Shamatha meditation is good for people who have too many thoughts; mind is too busy and negative thoughts. If you do Shamatha, you will be more peaceful; have less negativity and mind calms down.
Rigpashana is tantra visualization with the Refuge tree; Yidam (Samantabhadra, peaceful and wrathful yidams); Dakini (21 Tara and many different Taras and different Dakinis) and Dharmapala (peaceful and wrathful). These best benefit Shamatha meditation.
When you do Refuge then your mind will be more peaceful, happier and will have fewer negative thoughts because you are thinking of Buddha and the Four Roots with your mind. Four Roots with speech and mantra are not negative things but blessingful things. Body is with yoga – Four Roots mudra. Then your great Shamatha is peaceful, great Buddhahood and this is your body, speech and mind. Then exactly you see Four Roots. You see you are body, speech, and mind, great Shamatha with Buddha Dharma. Then you will easily do Rigpashana.
Rigpashana is understanding nature of body, speech and mind. Rigpashana body means you understand your physical body is really great Buddha, precious human life. Great Rigpashana of speech you understand the nature of mantra. Great mind you understand the nature of Buddha.
Shamatha is the cause of Rigpashana. If Shamatha is good, then actioin, fruition is Rigpashana. If you do Shamatha in a very good way then you do tantra way. You will understand tantra Rigpashana and Dzogchen.
In the Tantrayana way, first you do Refuge, Bodhicitta and visualization of Four Roots. This is Shamatha way. Then Rigpashana you recognize your yidams; you understand Mahamudra. It is excellent that you recognize nature of your mind – Dzogchen. This is tantra cause of action, or Shamatha and Rigpashana. This way you will have Shamatha very quickly and understand Rigpashana way easily. And very quickly have liberation mind this lifetime.
Usually Shamatha can be good and it can also be bad. In good Shamatha, concentration is very good and one feels peaceful. When Shamatha is not good, it is because there is attachment, desire and not thinking of others, only about oneself. One doesn’t recognize mind only attached to being peaceful. This is an obstacle to nirvana. A short time obstacle for liberation of the mind. This is because samsara Shamatha is ‘wonderful!’, peaceful! There are four Shamathas. But this is not liberation Shamatha. This is samsara Shamatha. Tantra Shamatha is nirvana. It is with Shamatha and Rigpashana because you understand Buddha; you understand nature of mind and all of these things.
In Buddha Jana. Khenchen Lama.