رِيَاضُ الصَّالِحِينَ
Riyad as-Salihin 1697
The Book of the Prohibited actions
Undesirability of Quarrelling or Raising voices in the Mosque
وَعَنْهُ أَنَّ رَسُولَ اَللَّهِ صَلَّى اللَّه عَلَيْهِ وَسَلَّمَ قَالَ: إِذَا رَأَيْتُمْ مَنْ يَبِيعُ أَوْ يَبْتَاعُ فِي الْمَسْجِدِ، فَقُولُوا: لاَ أَرْبَحَ اللَّهُ تِجَارَتَكَ، وَإِذَا رَأَيْتُمْ مَنْ يَنْشُدُ ضالة فقولوا: لاَ رَدَّهَا اللَّهُ عَلَيْكَ . رَوَاهُ التِّرْمِذِيُّ، وَقَالَ: (حَدِيثٌ حَسَنٌ).
Abu Hurairah (May Allah be pleased with him) said: The Messenger of Allah said, "When you see someone buying or selling in the mosque, say to him: 'La arbaha-Allahu tijarataka (May Allah not make your bargain profitable)!' When you see someone announcing something lost in it, say: 'May Allah not restore it to you!"' [At-Tirmidhi].
Riyad as-Salihin, 1697