GJT: abbr for "yan nas 'debs pa" which means to "purify from above" and refers to the process of purification thru the decent of amrita from Vajrasatta. The first of three modes of purification in Vajrasattva practice; the other two are {man 'debs} and {'phul 'debs}. In the {yan 'debs} process one imagines one's impurities pass out from one's seat along with the amrita. N.B. GJT said that "deb" had the sense of "to push" but did not know the spelling of "deb" so {'debs} is a best guess. See also {man 'debs} and {'phul 'debs} [mss]