Bhagavad-Gita: Chapter 7, Verse 18

Rudra Vaisnava Sampradaya:

Visnuswami

Sridhara Swami's Commentary

The question may arise that do the other three classes being the artta or afflicted, the artharthi or those desiring wealth and the jijnasuh or those desiring self realisation have to undergo transmigration and reincarnation? The answer is never. This is confirmed by Lord Krishna using the word udarah meaning noble and magnanimous. All these noble beings obtain moksa or liberation from the cycle of birth and death in the material existence; but the jnani or knower of God is His very atma or soul. This is because the jnani with his mind fixed solely upon the Supreme Lord, has taken complete refuge in Him alone as the only goal other than which there is nothing superior. So such a realised being is interested in no other purpose then attaining the Supreme Lord and thus devotes all there efforts for this.

Brahma Vaisnava Sampradaya:

Madhvacarya
There is no commentary for this verse.

Sri Vaisnava Sampradaya:

Ramanuja

Ramanuja's Commentary

Due to the fact that the previous four classes all resort to the Supreme Lord, they are all noble and udarah or magnanimous inasmuch as when they receive any benediction from Him it is as by their loving act of acceptance that the Supreme Lord feels bliss and is truly grateful to them for accepting His love. Lord Krishna considers the jnani or the knower of God as dear to Him as His own self and considers even that His very existence depends upon them. One may question how is this to be understood? One must understand that the Supreme Lord reciprocates in the same manner as His devotee acts towards Him. Thus in the same way that His devotee cannot live without Him, He cannot live without His devotee. Therefore His devotee atma or soul realised is His very life as the atma.

Kumara Vaisnava Sampradaya:

Nimbaditya

Kesava Kasmiri's Commentary

One may pose the question what about the other three types being artto the aflicted, atharthi or those seeking wealth and jnajinsuh or those seeking moksa or liberation. Are they wretched and unworthy? To the contrary and Lord Krishna confirms this with the word udarah meaning noble and magnanimous. All these devotees are noble beings who have accumulated great merit in the course of tens of thousands of previous births. No one can become a devotee of Lord Krishna if they only have a small amount of merit from previous lives. The devotees of the Supreme Lord Krishna have such a surplus of accumulated merit due to having practised austerities, undergone penance, performed yoga, engaged in meditation, offered prayers and given worship. That it is a natural course of events that in their early lives they attain the opportunity to be Lord Krishna's devotee. This is confirmed and corroborated in the Vedic scriptures by the statement: Humans whose sins are expired cultivate devotion to Lord Krishna. Others who still remain sinful never become Lord Krishna's devotee, they only can worship Kali, Ganesh or some impersonal phantasm conception. So for those aspirants of the three previous types who have the tinge of fruitive motivations, still they are the elect and after finally achieving devotion to Him they become free from desire and qualified for moksa or liberation from the cycle of birth and death. Lord Krishna accepts the jnani as His very self to exemplify their exalted position, because nothing is more dearer then oneself. For the jnani is the elite and the absolute devotee who is firmly established being time tested over a myriad of lifetimes. He is wholeheartedly devoted to the Supreme Lord as his only goal another of which there is nothing superior and having such faith assuredly arrives at that goal.