The same principle of working order is being discussed by Kṛṣṇa again in this verse. The beginning was cātur-varṇyaṁ mayā sṛṣṭaṁ guṇa-karma-vibhāgaśaḥ (BG 4.13). We should remember the same principle always. Four classes are divided according to quality and karma. Therefore Kṛṣṇa says, karmaṇo hy api boddhavyam. What is actually work. Boddhavyaṁ ca vikarmaṇaḥ. Vikarmaṇaḥ means forbidden. This is the human life's business. He should know what is actual work and what is forbidden work.