وَعَنْ أَبِي هُرَيْرَةَ أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ سَمِعَ رَجُلًا يَقْرَأُ (قُلْ هُوَ اللَّهُ أَحَدٌ) فَقَالَ: «وَجَبَتْ» قُلْتُ: وَمَا وَجَبَتْ؟ قَالَ: «الْجنَّة» . رَوَاهُ مَالك وَالتِّرْمِذِيّ وَالنَّسَائِيّ

The Prophet, on hearing a man reciting “Say, He is God, One” remarked, “It is certain.” I asked him what was certain, and he replied that it was paradise. Mālik, Tirmidhī and Nasā’i transmitted it.