Imam al-Sadiq (AS) said,
ـ الإمامُ الصّادقُ (عَلَيهِ الّسَلامُ): علَيكُم بِإتيانِ المَساجِدِ؛ فإنّها بُيوتُ اللّهِ في الأرضِ ، ومَن أتاها مُتَطَهِّراً طَهَّرَهُ اللّهُ مِن ذُنوبِهِ وكُتِبَ مِن زُوّارِهِ فَأكثِرُوا فيها مِن الصَّلاةِ والدُّعاءِ.
Imam al-Sadiq (AS) said, ‘It is incumbent upon you to attend the mosques, for verily they are the houses of Allah on earth. And whoever enters them having purified himself, Allah will purify him of his sins and will record him down as one of its frequenters, so perform many prayers and supplications therein.’[Amali al-Saduq, p. 293, no. 8]
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At least one gunman killed 49 people and wounded more than 20 during Friday prayers ...