18.66 'Relinishing all Dharmas means the complete relinishment of the sense of agency, possessiveness, fruits etc., in the practising of Karma, Jnana and Bhakti Yogas in the way instructed, and the realising of Me as the agent, object of worship, the means and the end. It means that relinishment is not of all devotional duties but only of the sense of agency and the fruits. This is the Sastraic relinishment of all Dharmas. It is firmly established in the beginning of this chapter commencing from, 'Listen regarding My decision, O Arjuna, about abandonment; for abandonment is declared to be of three kinds' (18.4), and 'Renouncing attachments and also the fruit, such abandonment is regarded as Sattvika ৷৷. for it is impossible for one who bears the body to abandon acts entirely. But he who gives up the fruits of works, is called the abandoner' (18.9-11).

If you practise such abandonment of the sense of agency and fruits, I will release you from all 'sins' - i.e., I will release you from all evil incompatible with the attainment of Myself, consisting of innumerable acts of the nature of doing what ought not to be done and not doing what ought to be done. These piled up from beginningless times from the obstruction in the way. Grieve not, you should not despair; for I shall release you from all these obstructions.

Another (alternative) explanation is this:  Bhakti Yoga is possible only for those people to whom the Lord is exceedingly dear and who are free from all evils. Those evils are so huge in their case that the expiatory rites which could wash them off, could not be performed in the limited time of one's life span. Ajuna therefore thought that he was unfit for commencing Bhakti Yoga. To remove the grief of Arjuna the Lord said:  'Completely relinishing all Dharmas, seek Me alone for refuge.' Expiatory rites can be taken here as what is meant by Dharma, Completely forsake these rites (Dharmas) appropriate for the removal of numerous and varied sins piled up from beginningless time and obstructing the starting of Bhakti Yoga. The expiatory rites consist of practices like Krcchra, Candrayana, Kusmanda, Vaisvanara, Vratapati, Pavitresti, Trvrit, Agnistoma etc., which are of manifold varieties, and which are difficult to perform on account of the brevity of life. So in order to succeed in commencing Bhakti Yoga, seek Me alone for refuge. I am supremely compassionate, the refuge of all without considering the differences of character among them, and am an ocean of tenderness for those dependent on Me. I will release you from all evil, the nature of which has been explained as incompatible with the commencement of Bhakti Yoga. Grieve not. [Both these interpretations of this famous verse are said to teach only Bhakti Yoga and not Prapatti. But the estion will rise in one's mind - why should it not be so taken?]