俱舍論疏 2.219

2.219

論「舌根極微至極微所遍」，此明舌根極微量也。述曰：准鼻、舌根，兩釋中後釋為善。若微傍布清徹暯覆令無分散，准此鼻、舌亦合如此。若如此師釋，三根必不取外香、味等，隔清暯故。若外香等非根所取，非執受香等恒彼同分，即不可說二識識也，亦無五識煩惱縛義，違眾多理、教。應依後釋為善。「傳說舌中如毛端量非為舌根極微所遍」者，此事難知，應竪如毛端量，非是橫也。論主不全信，故言傳說也。

The passage in the treatise from 'The atoms of the tongue faculty' up to 'is not pervaded by the atoms of the tongue faculty' explains the measure of the atoms of the tongue faculty. The commentary states: judging by the nose and tongue faculties, between the two explanations, the latter explanation is superior. If the atoms were arranged laterally and covered with a clear membrane to keep them from dispersing, then judging by this, the nose and tongue should also be like this. If it were according to that master's explanation, these three faculties would definitely not grasp external scents, tastes, and so on, because they would be blocked by the clear membrane. If external scents and so on were not grasped by the faculties, and scents not appropriated were perpetually of non-identical status, then it could not be said that the two consciousnesses cognize them, nor would there be the meaning of bondage by defilements in the five consciousnesses, which contradicts many rational arguments and teachings. One should follow the latter explanation as superior. As for 'It is said that in the tongue an area of the measure of a hair-tip is not pervaded by the atoms of the tongue faculty', this matter is difficult to know; it should be vertical like the measure of a hair-tip, not horizontal. The author of the treatise does not fully believe it, hence he says 'it is said'.