Bg 4.30

sarve ’py ete yajña-vido
yajña-kṣapita-kalmaṣāḥ
yajña-śiṣṭāmṛta-bhujo
yānti brahma sanātanam

Synonyms: 

sarve — all; api — although apparently different; ete — these; yajña–vidaḥ — conversant with the purpose of performing sacrifices; yajña–kṣapita — being cleansed as the result of such performances; kalmaṣāḥ — of sinful reactions; yajña–śiṣṭa — of the result of such performances of yajña; amṛta–bhujaḥ — those who have tasted such nectar; yānti — do approach; brahma — the supreme; sanātanam — eternal atmosphere.

Translation: 

All these performers who know the meaning of sacrifice become cleansed of sinful reactions, and, having tasted the nectar of the results of sacrifices, they advance toward the supreme eternal atmosphere.

 

From 4.30 till 4.33

Here Shri Krishna will describe the broad principle, purpose & essence of Yajna.

 

sarve ’py ete -> All these people; yajña-vido -> Knower of Yajna; yajña-kṣapita -> Become purified; kalmaṣāḥ -> of sinful reaction; yajña-śiṣṭā -< remnants of Yajna; āmṛta-bhujo -> remnants of yajna is amrit, when they taste this amrit (eternal or nectar); yānti brahma sanātanam -> They go to the eternal Brahman, eternal supreme

First result of Yajna is purification. Enjoy the fruits of the result and attain liberation. yānti brahma sanātanam  They attain eternal Brahman the ultimate spiritual platform. So in this way Krishna is saying we will become purified and get liberated. Now off course not all yajna leads to liberation with same degree and same speed, that will vary naturally because there are different level of commitment, different level of sacrifice in different kinds of Yajna but Krishna is giving us a unifying vision of everything, there is a diversity of forms, at one level a householder and other an astang yogi regulating their breath and there are others who are absorbed in study the cultural form will be different for all these people but there is unifying principle and purpose which is purification and liberation. yajña-kṣapita-kalmaṣāḥ -> one become purified from impurities and yānti brahma sanātanam -> gets liberation. The liberation is then personal and impersonal as Srila Prabhupad mentions.