CC Ādi 4.20
tāṁs tathaiva bhajāmy aham
manuṣyāḥ pārtha sarvaśaḥ
“ ‘In whatever way My devotees surrender unto Me, I reward them accordingly. Everyone follows My path in all respects, O son of Pṛthā.’
In the fourth chapter of the Bhagavad-gītā Lord Kṛṣṇa affirms that formerly (some 120 million years before the Battle of Kurukṣetra) He explained the mystic philosophy of the Gītā to the sun-god. The message was received through the chain of disciplic succession, but in course of time, the chain being broken somehow or other, Lord Śrī Kṛṣṇa appeared again and taught Arjuna the truths of the Bhagavad-gītā. At that time the Lord spoke this verse (Bg. 4.11) to His friend Arjuna.