Cite the scanned version of the original dicionary like this:
Toller, T. Northcote, and Joseph Bosworth. "laga." An Anglo-Saxon Dictionary: Based on the Manuscript Collections of the Late Joseph Bosworth : Supplement. Oxford: Clarendon Press, 1921. 604.
, an; m. Law :-- Stande án laga, L. C. S. 34; Th. i. 396, 22, MS. B. Rǽde gé forþ lagan fyrþor ic wolde gif mé tó anhagode proceed further in determining laws; I would, if it were convenient for me, Wulfst, 275, 11. v. riht-, woruld-laga.