I may not, madam.
My lady charged my duty in this business.

– William Shakespeare

King Lear, Act 4, Scene 5. At Gloucester’s castle, Oswald tells Regan that he cannot stay, as Goneril has ordered him to carry out her instructions. This shows his unquestioning loyalty and obedience to Goneril. Regan is trying to stop Oswald delivering Goneril’s love letter to Edmund.