‘Tis the time’s plague when madmen lead the blind.
Do as I bid thee, or rather do thy pleasure.
Above the rest, begone.

– William Shakespeare

King Lear, Act 4, Scene 1. Gloucester tells the Old Man that he can leave, and the "madman" (Edgar, who is not actually mad) can now lead the "blind" (Gloucester). Ironically when Gloucester was blind he didn’t trust Edgar, but now that he is blind he does.