The Messenger of Allah ﷺ said, "An accepted Hajj has no reward except Paradise, and two Umrahs expiate the sins committed between them."
حدثنا عبد الرحمن قال حدثنا سفيان عن سمي عن أبي صالح
قال رسول الله ﷺ الحج المبرور ليس له جزاء إلا الجنة والعمرتان تكفران ما بينهما من الذنوب
Its isnad is sahih. Bukhari related it, 3/2, in the book of Umrah, chapter on the obligation of Umrah, and Muslim, 2/983, number 1349, in the book of Hajj, similarly, and Tirmidhi, 3/263, number 933, and he said, hasan sahih, and Nasai, 5/112, number 2622, and Ibn Majah, 2/964, number 2888.