Ge-delfan

According to the Old English Dictionary:

ge-delfan

p. -dealf, pl. -dulfon; pp. dolfen To dig, delve;fodere, effodere :-- Wæs ðǽr sum hláw ðone men gedulfon there was a mound which men had dug, Guthl. 4; Gdwin. 26, 6. Ðé wearþ helle seáþ niðer gedolfen the pit of hell was dug beneath for thee, Exon. 71 b; Th. 267, 30; Jul. 423. ge-delfan