ya idaḿ paramaḿ guhyaḿ
mad-bhakteṣv abhidhāsyati
bhaktiḿ mayi parāḿ kṛtvā
mām evaiṣyaty asaḿśayaḥ

Translation of Bhagavad Gita 18.68

For one who explains this supreme secret to the devotees, pure devotional service is guaranteed, and at the end he will come back to Me.

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

Generally it is advised that Bhagavad-gita be discussed amongst the devotees only, for those who are not devotees will understand neither Krishna nor Bhagavad-gita. Those who do not accept Krishna as He is and Bhagavad-gita as it is should not try to explain Bhagavad-gita whimsically and become offenders. Bhagavad-gita should be explained to persons who are ready to accept Krishna as the Supreme Personality of Godhead. It is a subject matter for the devotees only and not for philosophical speculators. Anyone, however, who tries sincerely to present Bhagavad-gita as it is will advance in devotional activities and reach the pure devotional state of life. As a result of such pure devotion, he is sure to go back home, back to Godhead.

Commentary by Sri Vishvanatha Chakravarthi Thakur of Gaudiya Sampradaya:

This verse and the next state the results of giving instructions of bhakti. The instructor first attains parama bhakti (param bhaktim) and then the Lord himself (mam eva esyati).

Commentary by Sri Ramanuja of Sri Sampradaya:

18.68 One, who possessed of supreme devotion to Me, expounds this highest mystery to my devotees, shall come to Me, there is no doubt about this.

Commentary by Sri Sridhara Swami of Rudra Sampradaya:

Continuing further Lord Krishna confirms that there is no human more pleasing or dearer to Him any where in creation which according to the Bhagavat Purana comprises 400,000 species of human beings; then the devotee of His who reveals Srimad Bhagavad-Gita to His devotees. Nor will there be anyone more dear or pleasing to Him in the future.

Commentary by Sri Madhvacharya of Brahma Sampradaya:

Sri Madhvacharya did not comment on this sloka.

Commentary by Sri Keshava Kashmiri of Kumara Sampradaya:

One who establishes a forum for Srimad Bhagavad-Gita, giving the text as well as elaborate explanations of the meaning, doing this for the enlightenment of the devotees and not to receive honor or prestige, but only to please the Supreme Lord — such a devotee who does this service, disseminating this knowledge to the devotees, is serving the interests of Lord Krishna fully and will surely attain His communion. The mentioning of the word bhaktesu means Lord Krishna’s devotees, denoting that only by exclusive devotional service is one chosen to reside in the Supreme Lord’s eternal dhama or abode. The Katha Upanisad II.XXII, beginning nayam atma pravachanena, meaning: That devotee whom the Supreme Lord chooses by His own sweet will is the one who will attain Him. So it is established that loving devotion is what is essential to receive the Supreme Lord’s grace; even with the absence of austerities and such, a devotee is qualified to approach the Supreme Lord based on bhakti alone. So devotion is established as the only essential ingredient to attract the attention of the Supreme Lord. The understanding is that although determination and ritualistic Vedic knowledge are noteworthy and exemplary, they only bestow residence in the transitory heavenly planets and never the eternal spiritual realms, because they do not have the potency to attract the Supreme Lord, whose devotees are not subjected to results of a temporary nature but to results of an eternal nature. That is the difference in devotion and empirical knowledge.

Commentary by Sri Adi Shankaracharya of Advaita Sampradaya:

18.68 Yah, he who; abhi-dhasyati, will speak of, i.e., will present with the help of the text and its meaning, as I have done to you; imam, this; paramam, highest-that which has Liberation as its purpose; guhyam, secret, as spoken of above-(i.e.) the text in the form of a conversation between Kesava and Arjuna; madbhaktesu, to My devotees-. How will present? This is being stated: Krtva, entertaining; param, supreme; bhaktim, devotion; mayi, to Me, i.e., entertainting an idea thus-‘A service is being rendered by me to the Lord who is the supreme Teacher’-. Tho him comes this result: esyati, he will reach; mam, Me; eva, alone. He is certainly freed. No doubt should be entertained in this regard. By the repetition of (the word) bhakti (devotion) [In the word madbhaktesu.], it is understood that one becomes fit for being taught (this) Scripture by virtue of devotion alone to Him. Besides,

Commentary by Sri Abhinavagupta of Kaula Tantra Sampradaya:

18.69 Ca, and; tasmat, as compared with him, with the one who hands down the Scripture; na kascit, none else; manusyesu, among human beings; is priya-krt-tamah, the best accomplisher of what is dear; me, to Me, i.e., among the present human beings, surely none else other than him exists who is a better accomplisher of what I cherish. Moreover, na bhavita, nor will there be in future; anyah, anyone else, a second person; bhuvi, in he world, here; priyatarah, dearer; tasmat, than him. [It may be argued that, since for a seeker of Liberation meditation is the best means for It, therefore he will have no inclination to transmit scriptural teachings. To this the Lord’s answer is: One longing for Liberation has a duty to impart this scriptural teaching to one possessing the aforesaid qualities.]

Sanskrit Shloka Without Transliteration Marks:

ya idam paramam guhyam
mad-bhaktesv abhidhasyati
bhaktim mayi param krtva
mam evaisyaty asamsayah

Sanskrit to English Word for Word Meanings:

yaḥ — anyone who; idam — this; paramam — most; guhyam — confidential secret; mat — of Mine; bhakteṣu — amongst devotees; abhidhāsyati — explains; bhaktim — devotional service; mayi — unto Me; parām — transcendental; kṛtvā — doing; mām — unto Me; eva — certainly; eṣyati — comes; asaḿśayaḥ — without doubt.