BG 18.22

And that knowledge by which one is attached to one kind of work as the all in all, without knowledge of the truth, and which is very meager, is said to be in the mode of darkness.

18.22. That [instrument-of-knowledge], because of which, one, not realising the whole, gets indulged, without reason, in a particular activity, and which is unconcerned with the real nature of things and is insignificant - that is declared to be of the Tamas (Strand).

18.22 But that which clings blindly to one idea as if it were all, without logic, truth or insight, that has its origin in Darkness.

18-20-22 Sarvabhutesu etc. upto samudahrtam. In the classified ones : i.e., [classified] as gods, human beings, etc. Considers as [really] different : i.e., with the thought 'Here on this depends my pleasure; here in that lies my displeasure'. Without reason : To take recourse to wrath, desire etc., slavishly under the influence of one's own addiction and also without examining the cause, in named as a thing born of the Tamas (Strand).

18.22 But that knowledge which clings to a 'single type of act' as what ought to be done, viz., act in the form of the worship of ghosts or evil spirits yielding very small fruits, as if it yielded all fruits; that work 'not founded on any reason for having attachment,' because it is not a source of all fruits; 'untrue' because it is based on a false view of things such as seeing differentiation in the nature of the Atman; 'insignificant', because the worship of ghosts and evil spirits yields poor results - for such reasons knowledge of this kind is declared to be Tamasika. After having thus classified the threefold division of knowledge relating to work according to Gunas in respect of a person who is alified for work, Sri Krsna explains the triple division of the acts that ought to be done, according to Gunas.

18.22 But tat, that knowledge; is udahrtam, said to be; tamasam, born of tamas; yat, which is; saktam, confined; ekasmin, to one; karye, from, to one body or to an external image etc., krtsnavat, as though it were all, as though it comprehended everything, thinking, 'The Self, or God, is only this much; there is nothing beyond it,'-as the naked Jainas hold that the soul conforms to and has the size of the body, or (as others hold) that God is merely a stone or wood-, remaining confined thus to one form; ahaitukam, which is irrational, bereft of logic; a-tattvarthavat, not concerned with truth-tattvartha, truth, means some-thing just as it is; that (knowledge) which has this (truth) as its object of comprehension is tattvarthavat; that without this is ; a-tattvarthavat-; and which, on account of the very fact of its being irrational, is alpam, trivial, because it is concerned with trifles or is productive of little result. This kind of knowledge is indeed found in non-discriminating creatures in whom tamas predominates. Now is being stated the threehold division of action:

18.22 But that knowledge is declared to be Tamasika which clings to one single act as if it were the whole, which is not founded on reason, and which is untrue and insignificant.

18.22 But that (knowledge) is said to be born of tamas which is confined to one form as though it were all, which is irrational, not concern with truth and triivial.