Ge-scerpan

According to the Old English Dictionary:

-scirpan, -scierpan;

ge-scerpan

p. te To sharpen; acuere :-- Ic gescirpe mín swurd I will sharpen my sword, Deut. 32, 41. Ðære culfran bilwitnesse gescierpan [-scirpan, Hat. MS.] to sharpen the simplicity of the dove, Past. 35, 1; Swt, 236, 23; Cot. MS. ge-scerpan