Word reached Abdullah bin Salam that the Prophet ﷺ had arrived in Madinah, so he came to him to ask him about certain matters. He said, "I am going to ask you about three things that only a prophet would know. What is the first of the signs of the Hour?"He replied, "As for the first of the signs of the Hour, it is a fire that will drive people from the east to the west."
أن عبد الله بن سلام بلغه مقدم النبي ﷺ المدينة، فأتاه يسأله عن أشياء فقال: إني سائلك عن ثلاث لا يعلمهن إلا نبي، ما أول أشراط الساعة؟ فقال: أما أول أشراط الساعة فنار تحشرهم من المشرق إلى المغرب.
Bukhari narrated it in the Merits of the Ansar (3938) from Hamid bin Umar, from Bishr bin Mufaddal, who said, Humayd narrated to us, Anas narrated to us, and he related it in detail. It is mentioned in its proper place, and its meaning will come later in the chapter on the tenth sign, the emergence of the fire that will gather the people.