Allah showed Abraham the way of realizing the secrets of the universe, in order to infer by this the oneness and greatness of the creator.

Allah said ( interpretation of the meaning ) : { And thus did We show Abraham the realm of the heavens and the earth that he would be among the certain [in faith]. So when the night covered him [with darkness], he saw a star. He said, "This is my lord."1 But when it set, he said, "I like not those that set [i.e., disappear]." And when he saw the moon rising, he said, "This is my lord." But when it set, he said, "Unless my Lord guides me, I will surely be among the people gone astray." And when he saw the sun rising, he said, "This is my lord; this is greater." But when it set, he said, "O my people, indeed I am free from what you associate with Allah. Indeed, I have turned my face [i.e., self] toward He who created the heavens and the earth, inclining toward truth, and I am not of those who associate others with Allah." } Quran ( 6 : 75 - 79 )