It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both), from the Prophet (peace and blessings be upon him), that he (peace and blessings be upon him) said: "An obligatory prayer (performed) in the Jami' Masjid (congregational mosque) is equal to a Hajj mabrur (an accepted Hajj), and a voluntary prayer is like an accepted Hajj; and prayer in the Jami' Masjid has been given superiority over (prayer in) other mosques by five hundred prayers."
Only Ata bin Abi Rabah narrated this hadith from Nafi', and only Nuh bin Dhakwan from Ata, while Zuhayr bin Abbad is alone in narrating it.
Hadith Referenceالمعجم الأوسط / باب الألف / 171
Hadith Gradingمحدثین:إسناده ضعيف، فيه نوح بن ذكوان ضعفه أبو حاتم
Hadith Takhrij«قال الهيثمي: وفيه نوح بن ذكوان ضعفه أبو حاتم «مجمع الزوائد ومنبع الفوائد، ج 2، ص 46»»