This instruction by the Supreme Personality of Godhead to His father and mother, who are eternally connected with Him, is especially intended for persons eager to return home, back to Godhead. One should never think of the Supreme Personality of Godhead as an ordinary human being, as nondevotees do. Kṛṣṇa, the Supreme Personality of Godhead, personally appeared and left His instructions for the benefit of all human society, but fools and rascals unfortunately think of Him as an ordinary human being and twist the instructions of Bhagavad-gītā for the satisfaction of their senses. Practically everyone commenting on Bhagavad-gītā interprets it for sense gratification. It has become especially fashionable for modern scholars and politicians to interpret Bhagavad-gītā as if it were something fictitious, and by their wrong interpretations they are spoiling their own careers and the careers of others. The Kṛṣṇa consciousness movement, however, is fighting against this principle of regarding Kṛṣṇa as a fictitious person and of accepting that there was no Battle of Kurukṣetra, that everything is symbolic, and that nothing in Bhagavad-gītā is true. In any case, if one truly wants to be successful, one can do so by reading the text of Bhagavad-gītā as it is. Śrī Caitanya Mahāprabhu especially stressed the instructions of Bhagavad-gītā: yāre dekha, tāre kaha 'kṛṣṇa'-upadeśa (CC Madhya 7.128). If one wants to achieve the highest success in life, one must accept Bhagavad-gītā as spoken by the Supreme Lord. By accepting Bhagavad-gītā in this way, all of human society can become perfect and happy.
It is to be noted that because Vasudeva and Devakī would be separated from Kṛṣṇa when He was carried to Gokula, the residence of Nanda Mahārāja, the Lord personally instructed them that they should always think of Him as their son and as the Supreme Personality of Godhead. That would keep them in touch with Him. After eleven years, the Lord would return to Mathurā to be their son, and therefore there was no question of separation.