The single report (khabar al-ahad)

Shaykh 'Ali al-Khafif holds acting on the solitary report (khabar al-ahad) obligatory when probability outweighs that the Prophet ﷺ said, did, or approved it — legal obligation hangs on likelihood, not certainty ¹. Denying its authority was the doctrine of some people of passions — the Rafida, the philosophers, some Mu'tazila — and it would annul the whole Sunna, for apart from the mutawatir the entire practical Sunna of prayer, zakat, fasting and hajj rests on solitary reports ². The Prophet himself relied on single informants in his missions.