Sahih al-Bukhari 6683
Sahih al-Bukhari · Book 83: Oaths and Vows · If one says: "By Allah! I will not speak today"
Narrated `Abdullah:
حَدَّثَنَا مُوسَى بْنُ إِسْمَاعِيلَ ، حَدَّثَنَا عَبْدُ الْوَاحِدِ ، حَدَّثَنَا الأَعْمَشُ ، عَنْ شَقِيقٍ ، عَنْ عَبْدِ اللَّهِ ـ رضى الله عنه ـ قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم كَلِمَةً وَقُلْتُ أُخْرَى " مَنْ مَاتَ يَجْعَلُ لِلَّهِ نِدًّا أُدْخِلَ النَّارَ " . وَقُلْتُ أُخْرَى مَنْ مَاتَ لاَ يَجْعَلُ لِلَّهِ نِدًّا أُدْخِلَ الْجَنَّةَ .
Allah's Messenger (ﷺ) said a sentence and I said another. He said, "Whoever dies while he is setting up rivals along with Allah (i.e. worshipping others along with Allah) shall be admitted into the (Hell) Fire." And I said the other: "Whoever dies while he is not setting up rivals along with Allah (i.e. worshipping none except Allah) shall be admitted into Paradise."