'Abdullah bin Mas'ud (May Allah be pleased with him) reported:
There were, about forty of us with Messenger of Allah (ﷺ) in a camp when he said, "Aren't you pleased that you will constitute one-fourth of the inhabitants of Jannah?" We said, "Yes". He again said, "Aren't you pleased that you will constitute one-third of the inhabitants of Jannah?". We said: "Yes." Upon this he (ﷺ) said, "By Him in Whose Hand Muhammad's soul is, I hope that you will constitute one-half of the inhabitants of Jannah; and the reason is that only Muslims will be admitted into Jannah; and you are no more compared to the polytheists than as a white hair on the skin of a black ox, or a black hair on the skin of a white ox."[Al-Bukhari and Muslim].
Arabic/English book reference: Book 1, Hadith 431