spiritual and physical purification (tahārah)

لَا تَقُمْ فِيهِ أَبَدًا ۚ لَّمَسْجِدٌ أُسِّسَ عَلَى ٱلتَّقْوَىٰ مِنْ أَوَّلِ يَوْمٍ أَحَقُّ أَن تَقُومَ فِيهِ ۚ فِيهِ رِجَالٌ يُحِبُّونَ أَن يَتَطَهَّرُوا۟ ۚ وَٱللَّهُ يُحِبُّ ٱلْمُطَّهِّرِينَ

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 Allāh loves those who purify themselves.