Sayyiduna Anas bin Malik (may Allah be pleased with him) says: A man entered the mosque to announce a lost item, and the Prophet (peace and blessings be upon him) said: "May you not find it."
Al-Tabarani recorded it in al-Mu'jam al-Awsat, and its narrators are thiqat (trustworthy). Al-Bazzar recorded it with a weak chain; other hadiths on this will come in the chapter on lost property.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 2043
Sayyiduna Thawban (may Allah be pleased with him) says: I heard the Prophet (peace and blessings be upon him) say: "Whomever you see reciting poetry in the mosque, say to him: 'May Allah shut your mouth!' Say this three times. Whomever you see announcing a lost item in the mosque, say three times: 'May you not find it!' And whomever you see buying and selling in the mosque, say: 'May Allah not make your trade profitable!'" The narrator says: the Prophet (peace and blessings be upon him) told us exactly this.
Al-Tabarani recorded it in al-Mu'jam al-Kabir through the narration of Abd al-Rahman bin Thawban from his father, and I have not found anyone who has mentioned him (that is, Abd al-Rahman bin Thawban).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 2044
Hadith Gradingمحدثین:إسنادہ ضعیف
Hadith Takhrij«أخرجه المعجم الكبير للطبراني برقم: 1454»
It is reported from Ibn Sirin, or perhaps someone else, that he said: Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) found a man announcing a lost item, so he silenced him, rebuked him and said: "We have been forbidden from this."
Al-Tabarani recorded it in al-Mu'jam al-Kabir. Ibn Sirin did not hear from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 2045