Enigma

Admit a fair stranger to knock at your door, Both naked and verily friendless and poor; Unless you receive me, must perish indeed, No generous friend, will for me intercede. Misterious no doubt, the case must appear, 'Till open'd to you, by the eye or the ear: Like other wise beings, I've always conceal'd Those things which with prudence could not be reveal'd. But carefully now, to my ditty attend: With you it remains, to bring life to its end; Whatever my fault, I've been faithful and just, Nor can be accus'd of betraying my trust.