Musnad Ahmad 30:2242

'Affan narrated to us, Shu'bah narrated to us, he said: 'Alqamah ibn Marthad informed me, he said: I heard Abu al-Rabi' narrating that he heard Abu Hurayrah, from the Prophet, peace and blessings of Allah be upon him, who said: "Four things in my nation they will not abandon: disparaging lineages, wailing (over the dead), saying 'we were given rain by the star of such-and-such,' and (the belief in) contagion." (The Prophet, peace and blessings of Allah be upon him, then said): "I bought a mangy camel—or it became mangy—so I placed it among a hundred camels, and they became mangy. Who infected the first one?"