Which preposition to use with faver

with Occurrences 1%

I shew; And in Latin I speake wordes a few, To faver with my predication, And for to stere men to devotion, Then shew I forth my long, christall stones, Ycrammed full of clouts and of bones; Relickes they been, as were they, echone! Then have I, in Latin a shoder-bone, Which that was of an holy Jewes shepe.

Which preposition to use with  faver