Volume 9, Book 93, Number 611:
Narrated ‘Abdullah:
I asked Allah’s Apostle “What is the biggest sin in the sight of Allah?” He said, “To set up rivals unto
Allah though He alone created you.” I said, “In fact, that is a tremendous sin,” and added, “What
next?” He said, “To kill your son being afraid that he may share your food with you.” I further asked,
“What next?” He said, “To commit illegal sexual intercourse with the wife of your neighbor.”