yeṣāḿ tv anta-gataḿ pāpaḿ
janānāḿ puṇya-karmaṇām
te dvandva-moha-nirmuktā
bhajante māḿ dṛḍha-vratāḥ

Translation of Bhagavad Gita 7.28

Persons who have acted piously in previous lives and in this life and whose sinful actions are completely eradicated are freed from the dualities of delusion, and they engage themselves in My service with determination.

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

Those eligible for elevation to the transcendental position are mentioned in this verse. For those who are sinful, atheistic, foolish and deceitful, it is very difficult to transcend the duality of desire and hate. Only those who have passed their lives in practicing the regulative principles of religion, who have acted piously and who have conquered sinful reactions can accept devotional service and gradually rise to the pure knowledge of the Supreme Personality of Godhead. Then, gradually, they can meditate in trance on the Supreme Personality of Godhead. That is the process of being situated on the spiritual platform. This elevation is possible in Krishna consciousness in the association of pure devotees, for in the association of great devotees one can be delivered from delusion.

It is stated in the Srimad-Bhagavatam (5.5.2) that if one actually wants to be liberated he must render service to the devotees (mahat-sevam dvaram ahur vimukteh); but one who associates with materialistic people is on the path leading to the darkest region of existence (tamo-dvaram yositam sangi-sangam). All the devotees of the Lord traverse this earth just to recover the conditioned souls from their delusion. The impersonalists do not know that forgetting their constitutional position as subordinate to the Supreme Lord is the greatest violation of God’s law. Unless one is reinstated in his own constitutional position, it is not possible to understand the Supreme Personality or to be fully engaged in His transcendental loving service with determination.

Commentary by Sri Vishvanatha Chakravarthi Thakur of Gaudiya Sampradaya:

Then who is qualified for bhakti? This verse answers. Those who have punya karma, who have destroyed sins partially, develop a predominance of sattva guna and diminished tama guna. The result of this is a decrease in illusion. Consequently they become less  attached. Then they have chance  association with my devotees. They then become completely free of sin by practice of worship. Being freed completely of illusion (dvandva moha nimukta), they become steady (drdha vratah) in worshipping me. Thus, one should not consider that punya karma is the cause of any bhakti.

For the Lord has said:

yam na yogena sankhyena dana-vrata-tapo-‘dhvaraih vyakhya-svadhyaya-sannyasaih prapnuyad yatnavan api

Even though one engages with great endeavor in the mystic yoga system, philosophical speculation, charity, vows, penances, ritualistic sacrifices, teaching of Vedic mantras to others, personal study of the Vedas, or the renounced order of life, still one cannot achieve Me. SB 11.12.9

In many places, it is stated that punya karmas are dependent on kevala bhakti, and not its cause.

Commentary by Sri Ramanuja of Sri Sampradaya:

7.28 However, there are some whose sins, accruing from beginningless time, which cause desire or hatred to the pairs of opposites and annual the tendency towards Me, have come to an end, i.e., have become weakened, through the accumulation of good actions in numerous births, They resort to Me, devoid of delusion produced by the Gunas, and worship Me alone in proportion to the excellence of their Karmas previously described. In order to attain deliverance form old age and death and for acquiring the supreme consummation of reaching Me, they remain steadfast in their vows. Sri Krsna enumerates what special things are to be known and what ought to be attained by these three classes of votaries of God:

Commentary by Sri Sridhara Swami of Rudra Sampradaya:

The question might arise how is it that some people are seen to exclusively worship the Supreme Lord Krishna? This is being answered with anta-gatam papam meaning those whose sins have been completely eradicated. This is due to having taken shelter of a pure devotee of Lord Krishna and becoming habituated to perform meritorious activities in the mode of pure goodness without desire for rewards. Once the reactions to past sinful activities are terminated the obstruction to realisation is neutralised and one is freed from the delusion arising from attraction and aversion to the dualities such as pleasure and pain, joy and grief, success and failure, etc. At this time one becomes qualified and is able to become devoted to Lord Krishna with determination, worshipping Him exclusively.

Commentary by Sri Madhvacharya of Brahma Sampradaya:

Lord Krishna is explaining that also there are some exceptions to the previous verse. Those of purified mind and cleansed heart who nearly dissolved all reactions to their activities in past lives due to meritorious spiritual accomplishments. They will be directly born into a family knowledgeable about the glories of the Supreme Lord and be receptive to spiritual activities right from the beginning and never be under the sway of delusion.

Commentary by Sri Keshava Kashmiri of Kumara Sampradaya:

The question may be raised that if embodied beings have been deluded from time immemorial since conception in the gross body why is it that some people are still seen exclusively worshipping the Supreme Lord? To this Lord Krishna answers with the words punya-karmanam meaning performers of virtuous deeds. Such persons having association of the Lord Krishna’s pure devotee and under His guidance are able to free themselves from all sins and thus in the next life are born directly into a spiritual family by such merits. The accumulated sins of previous lives which veil the light of consciousness have been dissolved and all erroneous knowledge along with it, by performance of meritorious spiritual activities for many lifetimes. All delusion in the form of reacting in attraction and aversion to the dualities such happiness and distress, pleasure and pain, success and failure, etc have been neutralised and hence one qualifies for knowledge of the ultimate truth with firm resolve to worship the Supreme Lord Krishna, the supreme controller, omnipotent and omniscient, the cause of all causes, the ultimate bestower of all benedictions and just rewards for all actions and who is an ocean of love for His devotees.

Commentary by Sri Adi Shankaracharya of Advaita Sampradaya:

7.28 Yesam jananam, those persons; tu, on the other hand; punya-karmanam, who are of virtuous deeds, in whom exist virtuous deeds that are the cause of purification of the mind; whose papam, sin; antagatam, has come to an end, is almost eradicated, attenuated; te, they; dvandva-moha-nirmuktah, being free from the delusion of duality as described; and drdhavratah, firm in their convictions-those who [Here Ast. adds, ‘sarva-parityaga-vratena, through the vow of relinquishing everything’.-Tr.] have the firm knowledge that the supreme Reality is such alone and not otherwise are called drdhavratah-; bhajante, adore; mam, Me, the supreme Self. Why do they worship? This is being answered:

Commentary by Sri Abhinavagupta of Kaula Tantra Sampradaya:

7.28 See Comment under 7.30

Sanskrit Shloka Without Transliteration Marks:

yesam tv anta-gatam papam
jananam punya-karmanam
te dvandva-moha-nirmukta
bhajante mam drdha-vratah

Sanskrit to English Word for Word Meanings:

yeṣām — whose; tu — but; anta-gatam — completely eradicated; pāpam — sin; janānām — of the persons; puṇya — pious; karmaṇām — whose previous activities; te — they; dvandva — of duality; moha — delusion; nirmuktāḥ — free from; bhajante — engage in devotional service; mām — to Me; dṛḍha-vratāḥ — with determination.