tomorrow they were to receive instruction from kamal khan himself , in bomb making ; how to pack nails , ball-bearings and scrap pieces of metal around slabs of explosives ; hide them in culverts , waste bins , rucksacks ; insert such explosive devices into canvas vests with special pockets sewn in and conceal them beneath loose fitting traditional robes ; how to connect a detonation button , run the wires across your chest , down the inside of your sleeve to within easy reach of your sweating , trembling hand ; be taught the mantra , 'it is my duty to die for allah , to go to him with the blood of many infidels at my feet , on my robes , splashed on my face ' .