Transliteration
sarve’pyete yajñā-vido yajñā kṣapita kalmaṣāḥ || 30 ||
yajñā-śiṣṭāmṛta bhujo yānti brahmā sanātanam |
Translation
All these performers who know the meaning of sacrifice become cleansed of sinful reaction, and, having tasted the nectar of the remnants of such sacrifice(yajna), they attain the supreme state of bramhan.
Purport
After explaining different types of Yajnas, Bhagvan Shri Krishna finally declares that all those people who perform any of the Yajnas[as described from Sh#24-29], get from the sinful reactions of the karma. As described in Ch3, that any karma performs always produced a result and hence binds the doer into the reaction of the karma except the one, that is that Yajna.
Ch3:Sh9
yajnaarthaat karmano'nyatra loko’yam karmabandhanah
tadartham karma kaunteya muktasangah samaachara || 3.9 ||
The world is in bondage to work unless they are performed for the sake of Yajna (work was done as a sacrifice to Bhagvan Vishnu). Therefore, O Son of Kunti, give up attachment and do your work as a sacrifice.
Yajna hence is the core principle of Karma Yoga which liberate humans from the bondage of reactions.
