The Prophet ﷺ said, "Performing Umrah during Ramadan equals a Hajj."
أن النبي ﷺ قال: عمرة في رمضان تعدل حجة.
Ibn Majah (2995) narrated it from Abu Bakr bin Abu Shayba, who said, Ahmad bin Abdul-Malik bin Waqid told us, who said, Ubaydullah bin Amr told us, from Abdul-Kareem, from Ataa, from Jabir, who mentioned it. Its isnad is sahih. Abdul-Kareem is Ibn Malik Jazari. Imam Ahmad (14795, 14882) also narrated it through this same route.