Riyad as-Salihin 1278
Ibn 'Abbas (May Allah be pleased with them) reported:
The Prophet (ﷺ) said, "(The performance of) 'Umrah during Ramadan is equal to Hajj (pilgrimage)." Or said, "Equal to the performance of Hajj with me." [Al-Bukhari and Muslim] .
وعن ابن عباس رضي الله عنهما، أن النبي صلى الله عليه وسلم قال‏:‏ ‏
"‏عمرة في رمضان تعدل عمرة أو حجة معي‏"‏‏.‏ ‏(‏‏(‏متفق عليه‏)‏‏)‏