BG Chap 18 - Kṛṣṇa's promise

Kṛṣṇa has promised here to Arjuna that one who practices pure devotional service as described in verses 65 and 66 will return to His abode. Can one accept Kṛṣṇa's promise?

One might think that Kṛṣṇa had said that He would return to Vraja from Mathurā but did not keep His word. If one has such a doubt, Kṛṣṇa says here that He promises after making an admission that Arjuna is dear to Kṛṣṇa. Kṛṣṇa says that under oath He declares that Arjuna is dear to Him, and no one cheats a person dear to himself. If the resident of Mathurā, having an affectionate mind, does not cheat the one He loves, then what to speak of one He loves the most? Kṛṣṇa cannot tolerate the absence of such a person, and thus Arjuna should trust Him when He says that Arjuna would indeed achieve Him.

In his commentary on Bhāgavatam Viśvanātha explains that Kṛṣṇa kept His promise and returned to Vraja after three months in Mathurā. He had two forms. The manifest form stayed in Mathurā. The invisible form went back to Vraja to keep His promise to His highest devotees. At this time the devotees of Vraja also took two forms. The manifested form remained in separation and the invisible forms associated with the invisible Kṛṣṇa for eternal pastimes.