Is it farther or further?
Old English bihaldan (West Saxon behealdan) "give regard to, hold in view," also "to keep hold of, to belong to," from be- + haldan, healdan (see hold). Related: Beheld; beholding. A common West Germanic compound, cf. Old Saxon bihaldan "hold, keep," Old Frisian bihalda, Old High German bihaltan, German behalten, but "[t]he application to watching, looking, is confined to English" [OED].