Musnad Ahmad 30:3144

Waki’ and ‘Abd al-Rahman narrated to us, from Sufyan, from Mansur, from Abu Hazim, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever performs Hajj to the House, and does not commit sexual obscenity (rafath), and does not commit wickedness (fusuq), returns as he was the day his mother gave birth to him." ‘Abd al-Rahman said: "He emerges from his sins like the day his mother gave birth to him, or as he emerged from his mother's womb."