GJT: {'phul 'debs pa} "purify through pushing" refers to the third, and final, of three modes of purification in Vajrasattva practice; the first two being {yan 'debs} and {'phul 'debs}. Having purified from above and below, the practitioner now imagines that any remaining impurities are concentrated in the heart area and then forcefully purified, as if by a jet or stream of water, by the amrita from Vajrasattva which causes them to dissipate from the heart region into space. 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 {yan 'debs} and {man 'debs} [mss]