Musnad Ahmad 2:213

Ya'qub narrated to us, my father narrated to us, from Salih. Ibn Shihab said: Salim said: I heard Abdullah ibn Umar saying: Umar said: "Send for a physician to look at this wound of mine." He said: So they sent for a physician from the Arabs, and he gave Umar *nabidh* (fermented drink) to drink. The *nabidh* resembled blood when it came out of the stab wound that was below the navel. He said: So I called another physician from the Ansar, from the tribe of Banu Mu'awiyah, and he gave him milk to drink. The milk came out of the stab wound pure and white. The physician said to him: "O Commander of the Faithful, make your will." Umar said: "The brother of Banu Mu'awiyah has told me the truth, and had I said otherwise, I would have belied you." He said: The people wept for him when they heard that. He said: "Do not weep for us. Whoever is going to weep, let him leave. Have you not heard what the Messenger of Allah, peace and blessings of Allah be upon him, said? He said: 'The deceased is punished by the weeping of his family over him.'" Because of that, Abdullah would not allow anyone to weep in his presence over any of his children or others who had perished.