Srimad Bhagavad-Gita :
Chapter-5. ( Karma-sanyasa-yogam )
First 'Sakama-karmam', then 'Nishkama-karmam', lastly, 'Dyanam' ( Meditation ) -- these are the steps of Sadhana to develop and expand your 'Self ' ( Atma-vikasam').
This is not Sri Vyasa Maharishi's new theory.
The Vedik theory itself according to time, is made suitable and intelligible and re-established to the generations only --- Vyasa Bhagavan did.
It is found Veda-s are composed a plan / method of Sadhana , and indexed, for the Goal of Supreme Perfection.
The strength and beauty of nature has made wonder to ancient men, this is dealt with in the department / division/chapters of 'Mantra-s' of Veda-s.
The department / division /chapters 'Brapmana' deal with various karmas to fulfill desires.
Following 'Arnyakam' deal with the steps of sadhana for inner purification.
These are yajna-s, by discarding selfish desires, and having honest, sincere with fully surrender nature, to be followed.
To be continued ...