त्रिविधं नरकस्येदं द्वारं नाशनमात्मनः ।
कामः क्रोधस्तथा लोभस्तस्मादेतत्त्रयं त्यजेत् ॥ १६.२१ ॥

trividham narakasyedam dvāram nāśanam-ātmana: |
kāma: krodhas-tathā lobhas-tasmād-etat-trayam tyajet ||

Three-fold door to hell

Krishna now proceeds to summarize the whole enunciation of the chapter:

Passion, hatred and greed are the three-fold door to hell in this world. Therefore, these three are to be renounced.

This is where Bhagavad Gita excels. While he discusses the traditional and epic views on the subject, Krishna is quite sensitive and emphatic to add the final spiritual or Vedantic assessment in the matter. This alone is, of course, what counts ultimately.

Three are the doors, Krishna says, leading one to hell. These are nowhere other than in the mind of every one. When passion, hate or greed emerges in the mind, instantly open up the direct doors to hell too.

Where is hell in one’s own life then? It abides in the mind itself. These doors can be safely shut. That will verily bring victory over hell. Krishna’s statement is not new. He has been emphasizing it throughout.

In the second chapter, when analyzing the status and value of Vedas, particularly their ritualistic pronouncements, Krishna clearly stated how even the Vedic votary falls a victim to kāma, bhoga and aiśvarya, thereby abandoning all his discretion and discrimination (2.42-44).

In describing the sthitaprajña and sthitadhī also, he specifically pointed out how sanga (attachment) to an object grows into strong desire and greed, which then leads, step by step, to anger, hate, delusion and downfall (2.62,63). The same emphasis was again made in the 3rd chapter (3.34). In another way, he pointed out the same truth in the 5th chapter (5.23) too.

The warning against kāma and krodha continues throughout the discussion. Here too he refers to the same plight by describing the inner doors to hell. The main thread of the discussion thus becomes quite evident, emphatic and supreme.