The strange process of expulsion resumed , the hill peaking high with a pulsing movement and the skin tearing open . Rin could only hover in sympathetic agony while Manji bit down on a peeled stick and dug his fingers into the gravel . Again the emergence stopped and the rent began to heal , though the protrusion did n't retreat .

Question: Why would someone dig their fingers into gravel ?
Answer: Grasping the gravel is a way to change focus from the pain .Gravel grabbing is   a fun game .Gravel is a good commodity to build with .Gravel is good to have if you want to throw it .