Sayyiduna Sahl bin Hanzalah (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) passed by a camel whose back was sticking to its belly (due to hunger). So the Prophet (peace and blessings be upon him) said: "Fear Allah regarding these voiceless animals. Ride them when they are healthy, and eat them (by slaughtering) when they are in a sound condition."