Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates: The Prophet Muhammad (peace and blessings be upon him) said: "Whoever performs Hajj and does not engage in obscenity or sin, then when he returns, he is as (free from sins) as the day his mother gave birth to him (i.e., he is completely purified from sins)."
Hadith Referenceصحیح ابن حبان / كتاب الحج / 3694
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح - «حجة النبي صلى الله عليه وسلم»: ق.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده صحيح على شرط الشيخين