Jami` at-Tirmidhi Book 10, Hadith 35
The Prophet said: "He who slaps (his) cheeks, tears (his) clothes and calls with the call of the Jahliyyah is not one of us."
"When the news of the death of Ja'far came, the Prophet said: 'Prepare some food for the family of Ja'far, for indeed something has happened to them that will keep them busy.'"
"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.'"