Sayyidina Ibn Mas’ud (RA) reported that Allah’s Messenger (SAW) stood up between them and said, “There is no infection.” A villager said, “O Messenger of Allah! When a mangy camel mixes with other camels, they all are infected with mange.” He asked, “Then who brought mange to the first camel. (The illness of one does not come on another). Neither is there infection nor Safar. Allah created all souls and wrote down their life and their provision, and their hardships.”
[Ahmed 4198]