حَدَّثَنَا أَبُو كُرَيْبٍ، حَدَّثَنَا رِشْدِينُ بْنُ سَعْدٍ، عَنْ عَمْرِو بْنِ الْحَارِثِ، عَنْ دَرَّاجٍ، عَنْ أَبِي الْهَيْثَمِ، عَنْ أَبِي سَعِيدٍ، عَنْ رَسُولِ اللَّهِ ـ صلى الله عليه وسلم ـ قَالَ ‏"‏ إِذَا رَأَيْتُمُ الرَّجُلَ يَعْتَادُ الْمَسَاجِدَ فَاشْهَدُوا لَهُ بِالإِيمَانِ قَالَ اللَّهُ تَعَالَى ‏{إِنَّمَا يَعْمُرُ مَسَاجِدَ اللَّهِ مَنْ آمَنَ بِاللَّهِ}‏ الآيَةَ ‏.‏

It was narrated from Abu Sa'eed that: The Messenger of Allah said: "If you see a man frequenting the mosques, then bear witness to his faith. Allah says: 'The mosques of Allah shall be maintained only by those who believe in Allah and the Last Day. [At-Taubah: 18]'" Translation Not Available

Book Ref: Sunan Ibn Majah Book 4 Hadith 802
Web Ref:  Sunan Ibn Majah Vol 1 Book 4 Hadith 802