Musnad Ahmad 30:1173

Abu ‘Amir narrated to us, ‘Ikrimah ibn ‘Ammar narrated to us, from Damdam ibn Jawsa al-Yamami, who said: Abu Hurayrah said to me: "O Yamami, do not say to a man: 'By Allah, Allah will not forgive you,' or 'Allah will never admit you into Paradise.'" I said: "O Abu Hurayrah, this is a word one of us says to his brother and his companion when he is angry." He said: "Do not say it, for I heard the Prophet, peace and blessings of Allah be upon him, say: 'There were two men among the Children of Israel. One of them was diligent in worship, and the other was extravagant against his own soul. They were brothers. The diligent one would constantly see the other committing a sin and would say: "O you, desist." The other would say: "Leave me to my Lord; were you sent as a watcher over me?"'" He said: "Until one day he saw him committing a sin he deemed grave, so he said to him: 'Woe to you, desist.' He said: 'Leave me to my Lord; were you sent as a watcher over me?' He said: 'By Allah, Allah will not forgive you,' or 'Allah will never admit you into Paradise.'" He said: "Then Allah sent an angel to them, who took their souls. They gathered before Him, and He said to the sinner: 'Go and enter Paradise by My mercy.' And He said to the other: 'Did you have knowledge of Me? Were you capable of what was in My hand? Take him to the Fire.'" He said: "By the One in Whose hand is the soul of Abu al-Qasim, he spoke a word that ruined his worldly life and his Hereafter."