大毘盧遮那成佛經疏 13.136

13.136

次憍都褐羅菩薩（此譯謂除疑也，或除垢也。如大眾人皆有所疑怪之事不能決了，此菩薩即往其所而斷其疑網，以能為不請之友，常斷一切眾生疑惑，故以為名也）。其印作向內相叉拳合掌，申二火指頭相合，屈第三節，即是也（二空指如常在外竪也）。

Next is the Bodhisattva Kautūhala (translated as 'Dispelling Doubt,' or 'Dispelling Defilement.' When the assembly all have matters of doubt and astonishment that cannot be resolved, this bodhisattva proceeds to their place and cuts through their net of doubts; because he can serve as an uninvited friend and constantly cuts through the doubts and perplexities of all sentient beings, he is so named). His mudrā: interlock the fingers inward to form a fist-añjali, extend the two fire [middle] fingers with tips joined, and bend them at the third joint; this is it (the two space [thumbs] are erected outside as usual).