Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) narrates from the Prophet (peace and blessings be upon him) that he said: "Indeed, Allah has placed comfort and happiness in contentment and certainty through His justice and fairness, while He has placed grief and distress in doubt and displeasure." The narrator is in doubt about the word "happiness or ease" (as to which of these words was actually stated).