O you who acknowledge, do not ask about things, which if revealed to you, would harm you. If you ask about them after the Quran has been sent down, then they will become clear to you. God pardons for them, and God is Forgiving, Compassionate.
Translation endnotes
[5:101] The Quran explains and details all that we need for attaining salvation. Those who were not satisfied with the details provided by God, asked many trivial questions like some Jews asked before (2:67-71), and since they could not find answers in the Quran to their questions, they were attracted to hadith. Because of the great demand for more and more details on trivial issues, hadith narration and collection became a booming business. We are told many things ranging from, which order one should clip his or her fingernails in , and how long one should grow his beard, to which foot one should use to first step into the bathroom and on which side one should sleep on (9:31; 42:21).