首楞嚴義疏注經 10.259

10.259

現前根互用者，即前第三漸次證無生忍也，前文已見。從互用中入乾慧者，即此互用便是已入乾慧地也，互用即是自在位故。如前文云「返流全一，六用不行，乃至一切如來密圓淨妙皆現其中，此人即獲無生法忍。從是漸修，隨所發行，安立聖位，是則名為第三增進修行漸次，斯則始從乾慧終至等覺，俱不離此第三漸次而建立也。」今約從總入別，故云從互用中入也。言金剛者，以此行人從始至終皆由修習金剛三昧而得成就。故前文云「是種種地，皆以金剛觀察如幻十種深喻，奢摩他中用諸如來毘婆舍那，清淨修證，漸次深入。」或可此約利根之者，到乾慧地精心發化，遂超因位，直入妙覺，故得別受金剛之號。若鈍根者，隨所發行，更歷諸位，故不得受金剛之名，但稱乾慧耳。若將此位立在等覺後心，其如前文，彼文云「如來逆流，如是菩薩順行而至，覺際入交，名為等覺。」豈可於入交彼更立乾慧地耶？古人迷此，於等覺後更立金剛乾慧一位，誠誤後學，理例俱無，不敢聞命。

Regarding the present mutual use of the faculties: this is the attainment of the forbearance of non-arising dharmas in the third gradual step described previously, which has already appeared in the earlier text. Regarding entering the stage of dry wisdom from within mutual use: this very mutual use is having already entered the dry wisdom stage, because mutual use is the stage of sovereign mastery. As the earlier text stated: 'Turning back the flow and making it completely one, the six functions no longer operate, and even the secret, perfectly round, pure, and wondrous [states] of all tathāgatas appear within it; this person immediately attains the forbearance of non-arising dharmas. Gradually cultivating from this, in accordance with the practice brought forth, one establishes the noble stages. This is called the third gradual step of increasing practice.' This means that from dry wisdom up to equal enlightenment, none is established apart from this third gradual step. Here, speaking in terms of entering the specific from the general, it says 'enters from within mutual use.' As for the term 'vajra': this is because this practitioner, from beginning to end, attains accomplishment entirely through cultivating the vajra-samādhi. Thus the earlier text stated: 'These various stages are all purified, cultivated, and verified through vajra-contemplation of the ten deep metaphors of illusion-like [dharmas], using the tathāgatas' vipaśyanā within śamatha, gradually entering deeper.' Alternatively, this may refer to one of sharp faculties who, upon reaching the dry wisdom stage, has their purified essence of mind bring forth transformation and thereby surpasses the causal stages to enter directly into wondrous enlightenment; hence it specifically receives the title 'vajra.' If one is of dull faculties, in accordance with the practice brought forth one further traverses the various stages, and therefore does not receive the name 'vajra,' being called simply 'dry wisdom.' If one were to establish this stage after the final mind of equal enlightenment, how could that agree with the earlier text? That text stated: 'The Tathāgata flows against the stream; such a bodhisattva advances with the current; where the bounds of enlightenment intersect is called equal enlightenment.' How could one further establish a dry wisdom stage beyond that intersection? Ancient masters were confused about this and established an additional stage of 'vajra dry wisdom' after equal enlightenment; this truly misleads later students. Having neither doctrinal principle nor textual precedent, I dare not follow it.