Bundles of grasping-fuel: the upādāna-kkhandhas or grasping-aggregates/groups/bundles. These are material form (the body), feeling, perception, the constructing/volitional activities and consciousness, all of which we generally grasp at as "I." In the above discourse, one might see "birth... death" as particularly related to the khandha of material form, "sorrow... distress" as particularly related to that of feeling, and "union... not to get what one wants" as involving activities and perceptions. All involve consciousness. The common translation of upādāna-kkhandhā as "groups/aggregates of grasping" is wrong, as only part of the khandha of constructing/volitional activities is actual grasping. The khandhas are the object of grasping, upādāna. Moreover, "upādāna" also means fuel, that which is "taken up" by fire, here the "fire" of grasping and the other defilements. "Bundles of grasping-fuel" captures both these connotations of "upādāna." On this, cf. ch.2 of Thanissaro Bhikkhu, The Mind Like Fire Unbound, 1993., Barre, Mass.: Dhamma Dana Publications. The fuel-like nature of the khandhas is explicitly referred to at S iii 33-4 and M i 140-1 (MN 22 - just above "Well-proclaimed Dhamma" section), which compare the khandhas, as "not yours," to grass, sticks, branches and foliage being collected to be taken away and burnt. S iv 19-20 (SN 35.28) describes the six senses, their objects, their related consciousnesses, stimulations and feelings as all "burning" with attachment, hatred and delusion and "with birth, aging, death; with sorrow, lamentation, pain, unhappiness and distress," i.e., with causes of pain, and with things that are painful.