All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
The mentioned Hadeeth is authentic and was narrated by An-Nasaa’i in his book As-Sunan Al-Kubra; Al-Haakim in his book Al-Mustadrak, and he classified it as authentic; At-Tirmithi in his book Sunan At-Tirmithi, and he classified it as Hasan (sound); and Ibn Hibbaan in his book Saheeh Ibn Hibbaan. A group of scholars, such as Shaykh Al-Albaani and Shu‘ayb Al-Arnaa’oot, classified its chain of narration as authentic. The commentators of Hadeeth said that the statement of the Prophet : “Whoever says it in his illness and then dies, Hellfire shall not consume him,” means whoever says these words without saying the responses to them (that are mentioned in the Hadeeth). The following is stated in Tuhfat Al-Ahwathi: “Whoever says them; i.e. these words without their responses and then dies, i.e. from that illness, Hellfire shall not consume him.” [End of quote]
This clearly indicates that the intended meaning is that he says all these statements from beginning to end (without the responses to them).
Note: The words that are mentioned in the Hadeeth (without the responses by Allah to them) are the following: لاَ إِلَهَ إِلاَّ اللَّهُ وَاللَّهُ أَكْبَرُ ، لاَ إِلَهَ إِلاَّ اللَّهُ وَحْدَهُ ، لاَ إِلَهَ إِلاَّ اللَّهُ وَحْدَهُ لاَ شَرِيكَ لَهُ ، لاَ إِلَهَ إِلاَّ اللَّهُ لَهُ الْمُلْكُ وَلَهُ الْحَمْدُ، لاَ إِلَهَ إِلاَّ اللَّهُ وَلاَ حَوْلَ وَلاَ قُوَّةَ إِلاَّ بِاللَّهِ
Allah Knows best.