Majma al-Zawaid — Hadith 17483

Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates: We used to say about the one who kills a believer that when he dies he will go to Hell, and about the one who commits a major sin and then dies in that state, we used to say that he will go to Hell, until this verse was revealed: "Indeed, Allah Almighty will not forgive that a partner be associated with Him, and besides that He will forgive whomever He wills." The narrator says: So we did not declare anything binding for those people; we had hope for them and were also fearful for them.
Al-Tabarani recorded it in al-Mu'jam al-Kabir and al-Mu'jam al-Awsat. Its chain contains a narrator, Umar bin al-Mughirah, who is majhul (unknown), and the remaining narrators of this narration are the narrators of the Sahih. He also recorded it with another chain containing a narrator, Umar bin Buraydah al-Sayyari, whom I do not know; through him
this narration is reported from Muslim bin Khalid al-Zanji, who has been declared trustworthy, and the remaining narrators of this narration are the narrators of the Sahih.