لَا تَقُمْ فِيْهِ اَبَدًاۗ لَمَسْجِدٌ اُسِّسَ عَلَى التَّقْوٰى مِنْ اَوَّلِ يَوْمٍ اَحَقُّ اَنْ تَقُوْمَ فِيْهِۗ فِيْهِ رِجَالٌ يُّحِبُّوْنَ اَنْ يَّتَطَهَّرُوْاۗ وَاللّٰهُ يُحِبُّ الْمُطَّهِّرِيْنَ ( التوبة: ١٠٨ )
Laa taqum feehi abadaa; lamasjidun ussisa 'alat taqwaa min awwali yawmin ahaqqu an taqooma feeh; feehi rijaaluny yuhibbona ai yatatahharoo, wallaahu yuhibbul mmuttah hireen (at-Tawbah 9:108)
Do not stand [for prayer] within it – ever. A mosque founded on righteousness from the first day is more worthy for you to stand in. Within it are men who love to purify themselves; and Allah loves those who purify themselves. (At-Tawbah  : 108)
1 Mufti Taqi Usmani
Do not ever stand there (in prayer). In fact, the mosque that was founded on Taqwā (piety) from the very first day has greater right that you stand in it. In it there are people who like to observe purity; and Allah loves those observing purity.