It is narrated from a man of Banu Asad bin Khuzaymah that he said: I asked Sayyiduna Abu Ayyub al-Ansari (may Allah be pleased with him): If one of us prays in his house, then comes to the mosque and the prayer is being held there, should he pray with them as well? I feel some unease in my heart about it. Sayyiduna Abu Ayyub (may Allah be pleased with him) replied: We asked the Prophet (peace and blessings be upon him) about that, and he said: "For him there is a double reward."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3641