More on Wings of Azrael from Infoplease:

• Wings of Azrael - Wings of Azrael (The). (See Azrael.) Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894 ...
• Azrael - Azrael (3 syl.). The angel that watches over the dying, and takes the soul from the body. The angel ...
• Dictionary of Phrase and Fable: W - Definitions, origins, and illustrative excerpts for words, phases, and literary allusions starting with "W"