Cite the scanned version of the original dicionary like this:
Toller, T. Northcote, and Joseph Bosworth. "sacian." An Anglo-Saxon Dictionary: Based on the Manuscript Collections of the Late Joseph Bosworth : Supplement. Oxford: Clarendon Press, 1921. 692.
;p. ode To strive, brawl :-- Gif men saciaþ si rixati fuerint viri, Ex. 21, 22. Fela sind ðe wyllaþ fracodlíce him betwýnan sacian many there are that will shamefully brawl among themselves, Homl. Th. ii. 294, 1. v. and-sacian; sacan.