184. Dua for One Announcing Lost Items in Mosque
Narrated Abu Hurairah: That the Messenger of Allah (ﷺ) said: "When you see someone announcing about something lost then say:
لَا رَدَّهَا اللَّهُ عَلَيْكَ
لَا رَدَّهَا اللّٰهُ عَلَيْكَ
laa raddahAllahu 'alaik
Translation
May Allah not return it to you.
This is because the mosques were not built for this purpose.