Where does “*wiþra-” come from?

*wiþra- (Proto-Germanic) comes from Proto-Germanic wiþrą, from Proto-Indo-European wī-tero-, from Proto-Indo-European wi — apart, asunder; away from, against.

Ancestry of “*wiþra-”, step by step

Step	Language	Word	Meaning
1	Proto-Germanic	wiþrą	toward, against
2	Proto-Indo-European	wī-tero-	further apart
3	Proto-Indo-European	wi	apart, asunder; away from, against

Words derived from “*wiþra-”

wiþer-
widar-

Every word from Proto-Indo-European wi →Every word from Proto-Indo-European wī-tero- →Every word from Proto-Germanic wiþrą →