Musnad Ahmad 30:2744

Muhammad ibn Ja‘far narrated to us, he said: Shu‘bah narrated to us, and Hajjaj said: Shu‘bah informed us, from ‘Alqamah ibn Marthad, from Abu al-Rabi‘, from Abu Hurayrah, from the Prophet (peace and blessings of Allah be upon him), who said: "There are four things in my nation from the affairs of the Pre-Islamic Period (Jahiliyyah) that they will not abandon: slandering lineages, wailing over the dead, saying 'we were given rain by the rising of such-and-such star,' and contagion: a man buys a mangy camel and puts it with a hundred camels, and they become mangy. So who infected the first one?"