Hadith #43 (Sahih Muslim)
Book: The Book of Faith
Narrator(s): Hamam bin al-Harith همام بن الحارث
Grade: Sahih

It is narrated on the authority of ‘Uthman that the Messenger of Allah (ﷺ) said. He who died knowing (fully well) that there is no god but Allah entered Paradise.

Source: https://parallelquran.com/hadith/sahih-muslim-43/