(19) بَابُ إِذَا قَالَ وَاللَّهِ لاَ أَتَكَلَّمُ الْيَوْمَ. فَصَلَّى أَوْ قَرَأَ أَوْ سَبَّحَ أَوْ كَبَّرَ أَوْ حَمِدَ أَوْ هَلَّلَ، فَهْوَ عَلَى نِيَّتِهِ
Narrated `Abdullah:
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."
Reference: Sahih al-Bukhari 6683
In-book reference: Book 83, Hadith 60
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 8, Book 78, Hadith 674