Musnad Ahmad 26:778

'Affan narrated to us, 'Abd al-Wahid ibn Ziyad narrated to us, al-Harith ibn Hasirah narrated to us, al-Qasim ibn 'Abd al-Rahman narrated to us, from his father, from Ibn Mas'ud, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said to us: "How will you be with a quarter of the people of Paradise? You will have a quarter of it, and the rest of the people will have three-quarters of it?" They said: "Allah and His Messenger know best." He said: "How will you be with a third of it?" They said: "That is more." He said: "How will you be with half of it?" They said: "That is more." Then the Messenger of Allah (peace and blessings of Allah be upon him) said: "The people of Paradise on the Day of Resurrection will be one hundred and twenty rows; you will be eighty rows of them."