It is narrated from Sayyiduna Usayd bin Zuhayr al-Ansari (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "One prayer (offered) in the Masjid of Quba is equal to an Umrah."
Hadith Referenceالمعجم الكبير للطبراني / باب الألف / 566