etan me saḿśayaḿ kṛṣṇa
chettum arhasy aśeṣataḥ
tvad-anyaḥ saḿśayasyāsya
chettā na hy upapadyate

Translation of Bhagavad Gita 6.39

This is my doubt, O Krishna, and I ask You to dispel it completely. But for You, no one is to be found who can destroy this doubt.

Commentary by Sri A.C. Bhaktivedanta Swami Prabhupada of Gaudiya Sampradaya:

Krishna is the perfect knower of past, present and future. In the beginning of the Bhagavad-gita, the Lord said that all living entities existed individually in the past, they exist now in the present, and they continue to retain individual identity in the future, even after liberation from the material entanglement. So He has already cleared up the question of the future of the individual living entity. Now, Arjuna wants to know of the future of the unsuccessful transcendentalist. No one is equal to or above Krishna, and certainly the so-called great sages and philosophers who are at the mercy of material nature cannot equal Him. Therefore the verdict of Krishna is the final and complete answer to all doubts, because He knows past, present and future perfectly—but no one knows Him. Krishna and Krishna conscious devotees alone can know what is what.

Commentary by Sri Vishvanatha Chakravarthi Thakur of Gaudiya Sampradaya:

Etat (etan) stands for etam (accusative case).

Commentary by Sri Ramanuja of Sri Sampradaya:

6.37 – 6.39 Arjuna said — What way does he go, who has embarked on Yoga endowed with faith, but who by inadequacy of exertion in practice, does not gain success in Yoga and has his mind wandering from Yoga? Does he not perish like a small piece of cloud torn from a large mass of cloud — perish without reaching another large mass of cloud? Now does he not fall away from both (sides)? He has no support and is confused on the path leading to the Brahman. He is without any support in the sense that Karma or rituals which constitutes the means of heaven etc., does not give support for a person who is devoid of attachment to fruits; for Karma is the means for generating its own fruits. He is also confused in the path leading to the Brahman on which he has just begun to traverse; He has lost his way. Does he then get lost by falling down from both sides, these being attainment of heaven on the one hand and liberation on the other. Does he not thus perish? You should remove this doubt altogether from my mind; for there is no other remover of this doubt than You, who always perceive directly all matters simultaneously.

Commentary by Sri Sridhara Swami of Rudra Sampradaya:

Now Lord Krishna is being beseeched by Arjuna to definitely dispel his doubts as other than the omniscient and omnipotent Supreme Lord there is no one else who can remove it.

Commentary by Sri Madhvacharya of Brahma Sampradaya:

Sri Madhvacharya did not comment on this sloka.

Commentary by Sri Keshava Kashmiri of Kumara Sampradaya:

Lord Krishna is being requested to dispel all doubts concerning the destination of one who does not succeed in their life in perfecting yoga or the science of the individual consciousness attaining communion with the ultimate consciousness. All embodied beings are perishable and devoid of omniscience so as the omniscient Supreme Lord and most affectionate friend it would behove Him to completely clear up this question.

Commentary by Sri Adi Shankaracharya of Advaita Sampradaya:

6.39 O krsna, arhasi, You should; asesatah, totally; chettum, eradicate, remove; etat, this; samsayam, doubt; me, of mine. Hi, for; na tvad anyah, none other than You, be he a sage or a god; upapadyate, can be; chetta, the despeller, the destroyer; asya, of this; samsayasya, doubt. Therefore you Yourself should dispel (the doubt). This is the meaning.

Commentary by Sri Abhinavagupta of Kaula Tantra Sampradaya:

6.37-39 Ayatah etc. upto na hyupapadyate. Even if his mind has moved away from the Yoga, he had reached, the faith in [his] mind is not lost. for, a person – even if he has achieved the Yoga – makes all [achievements] useless, if his faith is completely lost. That has been said :- ‘Even after attaining the perfect knowledge, if it gets vitiated due to the caprices of mind, that very moment it perishes soon, just as a heap of cotton does due to fire’. If a complete success in the Yoga has not been achieved, then having come out of this [material] world, and having not yet got himself absorbed in the Brahman, would he get lost ? Or, because he has not yet got established in the Brahman, does he permanently get destroyed as the other world (heaven) is [also] ruined for him ? This is the question. On this [question], the conclusion –

Sanskrit Shloka Without Transliteration Marks:

etan me samsayam krsna
chettum arhasy asesatah
tvad-anyah samsayasyasya
chetta na hy upapadyate

Sanskrit to English Word for Word Meanings:

etat — this is; me — my; saḿśayam — doubt; kṛṣṇa — O Kṛṣṇa; chettum — to dispel; arhasi — You are requested; aśeṣataḥ — completely; tvat — than You; anyaḥ — other; saḿśayasya — of the doubt; asya — this; chettā — remover; na — never; hi — certainly; upapadyate — is to be found.