Mustadrak al-Hakim — Hadith 7837

It is narrated from Sayyiduna Abu Musa al-Ash'ari (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "This Ummah will be gathered divided into three groups: one group that will enter Paradise without reckoning, one group whose reckoning will be light (easy), and one group that will come carrying sins like firm mountains on their backs. Allah Almighty will ask about them - though He knows them best - Who are these people? They (the angels) will say: These are servants from among Your servants. Then Allah will say: Remove (the burden of their sins) from them and place it upon the Jews and the Christians, and admit them into Paradise by My mercy."