midnight
The song of the nightingale will sooner blight the rose-bower she loves than will the words of the Soldan offend the ears of the lovely kinswoman of England . '' `` Then , '' said the knight , `` I will bear the Soldan 's letter faithfully , as if I were his born vassal -- understanding , that beyond this simple act of service , which I will render with fidelity , from me of all men he can least expect mediation or advice in this his strange love-suit . '' `` Saladin is noble , '' answered the Emir , `` and will not spur a generous horse to a leap which he can not achieve . Come with me to my tent , '' he added , `` and thou shalt be presently equipped with a disguise as unsearchable as midnight , so thou mayest walk the camp of the Nazarenes as if thou hadst on thy finger the signet of Giaougi . '' -LSB- Perhaps the same with Gyges . -RSB- A grain of dust Soiling our cup , will make our sense reject Fastidiously the draught which we did thirst for ; A rusted nail , placed near the faithful compass , Will sway it from the truth , and wreck the argosy . Even this small cause of anger and disgust Will break the bonds of amity ` mongst princes , And wreck their noblest purposes .