It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: "Whoever performs such a Hajj in which he neither engages in sexual relations with his wife nor indulges in sin, then he returns (purified) as if his mother has just given birth to him."
Hadith Referenceصحيح ابن خزيمه / كتاب: المناسك / 2514