In one narration recorded by him, the wording is: Sayyiduna Ali (may Allah be pleased with him) had invoked against whoever concealed it.
The narrators of al-Mu'jam al-Awsat are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب المناقب / 14620
Hadith Gradingمحدثین:إسنادہ صحیح
Hadith Takhrij«اخرجه الطبراني فى المعجم الكبير (4985)»