Paradise and the Peri
The second tale in Moore's poetical romance of Lalla Rookh. The Peri laments her expulsion from Heaven, and is told she will be readmitted if she will bring to the Gate of Heaven the “gift most dear to the Almighty.” First she went to a battle-field, where the tyrant Mahmoud, having won a victory, promised life to a young warrior, but the warrior struck the tyrant with a dart. The wound, however, was not mortal, so “The tyrant lived, the hero fell.” The Peri took to Heaven's Gate the last drop of the patriot's blood as her offering, but the gates would not open to her. Next she flew to Egypt, where the plague was raging, and saw a young man dying; presently his betrothed bride sought him out, caught the disease, and both died. The Peri took to Heaven's Gate the last sigh of that self-sacrificed damsel, but the offering was not good enough to open the gates to her. Lastly, she flew to Syria, and there saw an innocent child and guilty old man. The vesper call sounded, and the child knelt down to prayer. The old man wept with repentance, and knelt to pray beside the child. The Peri offered the Repentant Tear, and the gates flew open to receive the gift.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894