It is narrated from Sayyiduna Sahl bin Hunayf (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever came to the Mosque of Quba and prayed in it, it became for him equal to an Umrah."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5538