Bhagavad Gita: Chapter 3/Verse 37

Chapter 3/Verse 37

श्रीभगवानुवाच
काम एष क्रोध एष रजोगुणसमुद्भवः ।
महाशनो महापाप्मा विद्ध्येनमिह वैरिणम् ॥३- ३७॥

śrībhagavānuvāca
kāma eṣa krodha eṣa rajoguṇasamudbhavaḥ ।
mahāśano mahāpāpmā viddhyenamiha vairiṇam ॥3- 37॥

The Blessed One said:
This desire [and] this anger are rajas. Based in the guṇa [rajas] is great consumption and great sin. Here you must know this enemy [rajas]. 

Word-for-word translations

śrībhagavān (masculine, nominative, singular) = the Blessed One (epithet of Krishna)

uvāca (past tense, 3rd person, singular) = said

kāmas (masculine, nominative, singular) = desire 

eṣas (adjective) (masculine, nominative, singular) = this

krodhas (masculine, nominative, singular) = anger 

eṣas (adjective) (masculine, nominative, singular) = this

rajas (neuter, nominative, singular) = rajas 

guṇasamudbhavas (guṇa + samudbhavas) (compound) (masculine, nominative, singular) = based in the guṇa

mahāśanas (mahā + aśanas) (compound) (masculine, nominative, singular) = great consumption 

mahāpāpmās (mahā + pāpmās) (compound) (masculine, nominative, singular) = great sin 

viddhi (imperative, 2nd person, singular) = you must know

enam (adjective) (masculine, accusative, singular) = this 

iha = here

vairiṇam (masculine, accusative, singular) = enemy

Commentary

From reviewing the past translations of this verse, it seems there is a lack of understanding in the copula clauses and the Sanskrit grammatical rules with applying adjectives to nouns. 

"This desire [and] this anger are rajas." is the first copula clause of the verse. One past translation believes that the second "this" in this verse is connected to "from a force" in the last verse, which is in the neuter gender, ablative case, and singular number. This violates the Sanskrit grammar rules when applying adjectives to nouns. "This" in this verse is an adjective, and thus must take on the gender, case, and number of the noun it modifies. In this case, it is modifying "krodhas", which has a masculine gender, nominative case, and singular number. 

The second error from previous translations is having "rajas", which is in the neuter gender, adjectivally modifying the compound "based in the guṇa", which is in the masculine gender. Following the same grammatical rule stated above, this is grammatically incorrect. "Rajas" is the latter part of the copula clause "Kāma eṣa krodha eṣa rajo..." in this verse. From this copula clause, it is then understood that rajas is the guna being alluded to in the first part of the second copula in this verse, "guṇasamudbhavaḥ mahāśano mahāpāpmā". 

Lastly, previous translations consider the enemy alluded to in this verse is great consumption and great sin verses the rajas. Once again, there is confusion about numbering in this part. "Enemy" is in the singular number and can only allude to a singular number word. "Enemy" cannot allude to both "great consumption and great sin". It would have to be in the dual number.