Jami` at-Tirmidhi Book 10, Hadith 36
"A man died among the Ansar named Qarazah bin Ka'b, and he was being wailed over. So Al-Mughirah bin Shu'bah came and ascended the Minbar. He uttered thanks and praise to Allah and said: "As for the gravity of wailing in Islam, indeed I heard the Messenger of Allah saying: 'The one who is wailed over is punished as long as he is being wailed over.'"
The Prophet said: "He who slaps (his) cheeks, tears (his) clothes and calls with the call of the Jahliyyah is not one of us."
"There are four matters in my nation that are from the matters of Jahiliyyah which the people will not leave: Wailing, slandering one's lineage, Al-Adwa - a camel gets mange, so one hundred camels get mange - but who gave the first camel mange? And Al-Anwa (saying): "We got rain because of this or that celestial positioning.'"