Musannaf Ibn Abi Shayba 6:1330

Muhammad ibn Bishr narrated to us, Muhammad ibn ‘Amr narrated to us, my father narrated to us, from ‘Alqamah ibn Waqqas, from ‘A’ishah, the Mother of the Believers, who said: The Messenger of Allah (peace and blessings of Allah be upon him), Abu Bakr, and ‘Umar were present—meaning at the [funeral of] Sa’d ibn Mu’adh. By the One in Whose hand is the soul of Muhammad, I truly recognize the weeping of ‘Umar from the weeping of Abu Bakr, and I was in my chamber. She said: And they were as Allah said: "Merciful among themselves." ‘Alqamah said: "O Mother, how would the Messenger of Allah (peace and blessings of Allah be upon him) act?" She said: "His eye would not shed tears for anyone, but when he was distressed, he would only take hold of his beard."