from Ubadah bin As-Samit, he said: "I entered upon him while he was dying, so I cried, and he said: "There now, why are you crying? For by Allah, if I am a martyr , then I will intercede for you, and if I can I will benefit you,' then he said: 'By Allah! There is no Hadith which I heard from the Messenger of Allah (ﷺ) which is good for you but I narrate it to you today, while I am near death. I heard the Messenger of Allah (ﷺ) say: "Whoever testifies to La Ilaha Illallah and that Muhammad is the Messenger of Allah, then Allah has forbidden the fire for him."
Jami` at-Tirmidhi Book 40, Hadith 33
← Previous Hadith Ibn 'Umar narrated that the Prophet (ﷺ) said: "Whoever says to his brother 'disbeliever' then it will have settled upon one of them." Sahih

Jami` at-Tirmidhi Book 40, Hadith 32 Next Hadith → that the Messenger of Allah (ﷺ) said: "Indeed Allah will distinguish a man from my Ummah before all of creation on the Day of Judgement. Ninety-nine scrolls will be laid out for him, each scroll is as far as the eye can see, then He will say: 'Do you deny any of this? Have those who recorded this wronged you?' He will say: 'No, O Lord!' He will say: Do you have an excuse?' He will say: 'No, O Lord!' So He will say: 'Rather you have a good deed with us, so you shall not be wronged today." Then He will bring out a card (Bitaqah); on it will be: "I testify to La Ilaha Illallah, and I testify that Muhammad is His servant and Messenger." He will say: 'Bring your scales.' He will say: 'O Lord! What good is this card next to these scrolls?' He will say: 'You shall not be wronged.' He said: 'The scrolls will be put on a pan (of the scale), and the card on (the other) pan: the scrolls will be light, and the card will be heavy, nothing is heavier than the Name of Allah.'"

Jami` at-Tirmidhi Book 40, Hadith 34