Abu Sa'id al-Khudri reported God’s Messenger as saying, “When you see a man frequenting the mosque, testify that he has faith, for God says, ‘God’s mosques are visited only by those who believe in God and the last day.”* * Al-Qur'an; 9:18 Tirmidhi, Ibn Majah and Darimi transmitted it.

عَنْ أَبِي سَعِيدٍ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: " إِذَا رَأَيْتُمُ الرَّجُلَ يَتَعَاهَدُ الْمَسْجِد فَاشْهَدُوا لَهُ بِالْإِيمَان فَإِن الله تَعَالَى يَقُولُ (إِنَّمَا يَعْمُرُ مَسَاجِدَ اللَّهِ مَنْ آمَنَ بِاللَّه وَالْيَوْم الآخر وَأقَام الصَّلَاة وَآتى الزَّكَاة) رَوَاهُ التِّرْمِذِيّ وَابْن مَاجَه والدارمي