Mukhtasar Bukhari (Abridged) 2168 — Book of Blood Money

Narrated Ibn Umar (may Allah be pleased with them) that the Messenger of Allah (peace and blessings of Allah be upon him) said: "A believer remains in a state of ease regarding his religion as long as he does not shed unlawful blood (i.e., when he sheds unlawful blood, he falls into corruption and hardship)."