On November 16, 2015, Rob (i.e. Robert Mayer, the Vajrakīla expert) posted on the facebook: “Can anyone point me to seriously detailed explanations of the rNying-ma Heruka’s wings? Primary sources preferred, secondary sources also appreciated.” In the follow-up responses, he explains that he is “looking for Tibetan exegeses of the meaning of the Heruka’s wings.” He goes on to state that the “various commentaries we have read so far, don’t go into as much detail as I would like.” He obviously found some explanations albeit not in detail. None of the responses that Rob received seemed to have served his purpose. When I read the posts, I wished I could be of some help but I had not the faintest idea. To begin with, I was thinking of the wings of Vajrakīla and not of any kind of Heruka. I had also hoped to find some explanations in Vajrakīla sādhana literature but I had not the time to screen through them, not even fleetingly. Rob’s enquiry did make me pay some attention to Vajrakīla-related sources that could potentially contain some explanations of Heruka’s wings. Thus far I was not able to find any explanation of the wings let alone detailed ones. But just now I accidentally bumped into something very brief. The Phur pa ’dus pa’i rtsa ba’i rgyud (p. 262.6), an important Tantric scripture of the Vajrakīla cycle from Nyang-ral’s bKa’ brgyad bde bshegs ’dus pa cycle of revealed treasures, states: rdo rje gshog (emended from gshogs) pa ma lus zil gyis gnon ¦ rin chen gshog pa dgos ’dod re ba bskong ¦ (“The vajra wings [symbolize] the overpowering of all [negative forces/elements]. The ratna wings [symbolize] the fulfillment of [all] needs and wishes.” Bibliography: Nyang-ral Nyi-ma-’od-zer (revealed), Phur pa ’dus pa’i rtsa ba’i rgyud. In bKa’ brgyad bde bshegs ’dus pa’i chos skor. 4 vols. Dalhousie: Damchoe Sangpo, 1977–1978, vol. 2, pp. 257–309. Indeed it will be interesting to trace detailed explanations of the symbol of vajra wings of Vajrakīla, but this little explanation is for the time being better than no explanation (at least for me). It is also possible that are no detailed explanations out there for it would actually suffice to state in one sentence: “Vajraic wings stand for x.” This does not, of course, shed any clue to the historical development of the iconology and semeiology of the Heruka’s wings.