E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
To finish Aladdins Windowi.e. to attempt to complete something begun by a great genius, but left imperfect. The genius of the lamp built a palace with twenty-four windows, all but one being set in frames of precious stones; the last was left for the sultan to finish; but after exhausting his treasures, the sultan was obliged to abandon the task as hopeless.
Taits second part of Drydens Absalom and Achitophel is an Aladdins Window.