Hayy Ponders Over Heaven and Stars
Thus far had he arrived with his reflections about the fourth septenary of his age. He recognised that the heavens and all the stars contained therein were bodies, because they are extended according to the three dimensions: length, breadth, and thickness.
Then he began to ask himself whether their extension was infinite, whether they extended to an endless length and breadth, or whether they were circumscribed by any bounds and terminated by certain limits.