حَدَّثَنَا يَعْقُوبُ بْنُ حُمَيْدِ بْنِ كَاسِبٍ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ وَهْبٍ، أَخْبَرَنِي حَيْوَةُ بْنُ شُرَيْحٍ، عَنْ مُحَمَّدِ بْنِ عَبْدِ الرَّحْمَنِ الأَسَدِيِّ أَبِي الأَسْوَدِ، عَنْ أَبِي عَبْدِ اللَّهِ، مَوْلَى شَدَّادِ بْنِ الْهَادِ أَنَّهُ سَمِعَ أَبَا هُرَيْرَةَ، يَقُولُ سَمِعْتُ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ يَقُولُ " مَنْ سَمِعَ رَجُلاً يَنْشُدُ ضَالَّةً فِي الْمَسْجِدِ فَلْيَقُلْ لاَ رَدَّ اللَّهُ عَلَيْكَ فَإِنَّ الْمَسَاجِدَ لَمْ تُبْنَ لِهَذَا " .
It was narrated from Abu 'Abdullah, the freed slave of Shaddad bin Had that: He heard Abu Hurairah say: "I heard the Messenger of Allah say: 'Whoever hears a man making a lost-and-found announcement in the mosque, let him say: "May Allah not return it to you!" For the mosques were not built for that.'" Translation Not Available
Book Ref: Sunan Ibn Majah Book 4 Hadith 767
Web Ref: Sunan Ibn Majah Vol 1 Book 4 Hadith 767