Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrates: The first to declare his Islam openly was Sayyiduna Umar bin al-Khattab (may Allah be pleased with him).
Tabarani recorded it, and its chain is hasan (good).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب المناقب / 14412
Hadith Gradingمحدثین:إسنادہ حسن۔
Hadith Takhrij«اخرجه الطبراني فى المعجم الكبير (10890)»