عَنْ أَبِي هُرَيْرَةَ قَالَ: سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ: «لَا طِيَرَةَ وَخَيْرُهَا الْفَأْلُ» قَالُوا: وَمَا الْفَأْلُ؟ قَالَ: «الْكَلِمَةُ الصَّالِحَة يسْمعهَا أحدكُم»

He reported God's messenger as saying, “There is no infection, no hama, and no serpent in a hungry belly." A nomadic Arab asked, “Messenger of God, how is it that when camels are in the sand as if they were gazelles* and a mangy camel comes among them it gives them mange?" God’s messenger replied, “Who infected the first one?" Bukhari transmitted it.* The comparison is used to indicate the clearness of their skin.