Musannaf Ibn Abi Shaybah 29790 — Killing one under a covenant

Sayyiduna Abdullah bin Amr (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: Whoever kills one under a covenant (mu'ahid) without right will not even smell the fragrance of Paradise, although its fragrance can be perceived from a distance of forty years' journey.