Sahih Muslim Book 001, Hadith Number 0430.
Chapter : This Ummah (Ummah of Islam) would constitute half of the inhabitants of Paradise.
Abu Sa'id reported: The Messenger of Allah (may peace be upon him) said: Allah, the High and Glorious, would say: O Adam I and he would say: At Thy service, at thy beck and call, O Lord, and the good is in Thy Hand. Allah would say: Bring forth the group of (the denizens of) Fire. He (Adam) would say: Who are the denizens of Hell? It would be said: They are out of every thousand nine hundred and ninety-nine. He (the Holy Prophet) said: It is at this juncture that every child would become white-haired and every pregnant woman would abort and you would see people in a state of intoxication, and they would not be in fact intoxicated but grievous will be the torment of Allah. He (the narrator) said: This had a very depressing effect upon them (upon the companions of the Holy Prophet) and they said: Messenger of Allah, who amongst us would be (that unfortunate) person (who would be doomed to Hell)? He said: Good tidings for you, Yajuj Majuj would be those thousands (who would be the denizens of Hell) and a person (selected for Paradise) would be amongst you. He (the narrator) further reported that he (the Messenger of Allah) again said: By Him in Whose Hand is thy life, I hope that you would constitute one-fourth of the inhabitants of Paradise. We extolled Allah and we glorified (Him). He (the Holy Prophet) again said: BY Him in Whose Hand is my life, I wish you would constitute one-third of the inhabitants of Paradise. We extolled Allah and Glorified (Him). He (the Holy Prophet) again said: By Him in Whose Hand is my life, I hope that you would constitute half of the inhabitants of Paradise. Your likeness among the people is the likeness of a white hair on the skin of a black ox or a strip on the foreleg of an ass.