Sayyiduna Abu Mas'ud al-Ansari (may Allah be pleased with him) said: The first of the Muhajirun to come to Madinah was Sayyiduna Mus'ab bin Umayr, and he was the first to lead the Friday prayer in Madinah on Friday, before the arrival of the Prophet (peace and blessings be upon him). He led them in (the Friday) prayer.
Imam al-Tabarani recorded this narration in al-Mu'jam al-Awsat and al-Mu'jam al-Kabir. Its chain contains a narrator, Salih bin Abi al-Akhdar, about whom there has been criticism.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 3076