Usul al-Kafi
Book 3: The Book of Excellence of Knowledge

Chapter 25
Nothing can come into existence in the heavens and earth without seven pre-existing entities

266. 2 Imam Musa al-Kazim (p): Nothing in this vast and mysterious universe exists without seven causes which are: The Decree of God, His Measure, His Resolution, His Will, Record in His Guarded Tablet; Predestined term, and His permission. Anyone who thinks otherwise attributes falsehood to God and denies the authority of God, the Mighty, the Majestic.