Cite the scanned version of the original dicionary like this:
Bosworth, Joseph. "manigteáw-ness." An Anglo-Saxon Dictionary: Based on the Manuscript Collections of the Late Joseph Bosworth. Ed. Thomas Northcote Toller. Oxford: Clarendon Press, 1898. 668.
.Add :-- Ðæt sunnan gér byð gesett on þrím hund dagum and fíf and syxtigum dagum and syx tídum þæs þe ásmeáde séo msenigtýwnes geþungenra wera, Angl. viii. 298, 5.