It is narrated from Hazrat Abu Duhha, may Allah have mercy on him: Regarding the martyrs of Uhud, this verse was revealed «وَلَاتَحْسَبَنَّالَّذِينَقُتِلُوافِيسَبِيلِاللَّهِأَمْوَاتًابَلْأَحْيَاءٌعِندَرَبِّهِمْيُرْزَقُونَ» and also this «وَيَتَّخِذَمِنْكُمْشُهَدَاءَ» about them. On that day, seventy people were martyred. Four were from the Muhajireen: Sayyiduna Hamza bin Abdul Muttalib (may Allah be pleased with him), Sayyiduna Mus'ab bin Umair (may Allah be pleased with him), Sayyiduna Shamas bin Uthman (may Allah be pleased with him), and Sayyiduna Abdullah bin Jahsh (may Allah be pleased with him). The rest were all from the Ansar.
Hadith Referenceسنن سعید بن منصور / كتاب الجهاد / 4070
Hadith Takhrij«أخرجه سعيد بن منصور فى «سننه» ترقيم الدرالسلفية برقم:، 538، 2894»