Forþ-swebban
Bosworth & Toller Anglo-Saxon Old English Dictionary - forþ-swebban
According to the Old English Dictionary:
-swefian;
- forþ-swebban
- p. -swefede; pp. -swefed To prevail, profit; profĭcĕre :-- Náht forþswefaþ fýnd nĭhil prōfĭciet inĭmīcus, Ps. Spl. T. 88, 22. forþ-swebban