It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "One Umrah to the next is an expiation for the sins between them, and the reward for an accepted Hajj is nothing but Paradise."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 10382