The Messenger of Allah forbade making lost-and-found announcements in the mosque.
Sunan Ibn Majah Book 4, Hadith 32
← Previous Hadith "The Messenger of Allah performed prayer, then a man said: 'Who was looking for the red camel?' The Prophet said: 'May you not find it! The mosques were built for that for which they were built.'"

Sunan Ibn Majah Book 4, Hadith 31 Next Hadith → 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.'"

Sunan Ibn Majah Book 4, Hadith 33