Abu Bara

Abū Barāʾ ʿĀmir ibn Mālik ibn Jaʿfar was the preeminent chieftain of the Arab tribe of Banu 'Amir during the time of the Islamic prophet Muhammad and interacted with the latter. During the expedition of Bi'r, four months after the Battle of Uhud, a delegation of Banu 'Amir came to Muhammad and presented him with a gift. Abu Bara' stayed in Medina. Muhammad declined to accept that gift because it was from a polytheist and asked Abu Bara' to embrace Islam. In response, Abu Bara' requested that Muhammad send some Muslims to the people of Najd to invite them to convert to Islam. At first, Muhammad was quite apprehensive of this, as he feared that some harm might befall on these Muslim missionaries. Yo assuage Muhammad’s hesitation, Abu Bara' guaranteed the safety of the Muslim emissaries. He stated,

"I will protect them."

Ibn Ishaq's Biography claims that forty men were sent to them; but Sahih al-Bukhari states that there were seventy — Al-Mundhir bin ‘Amr, one of Banu Sa‘ida, nicknamed ‘Freed to die’ — commanded that group, who were the best and most learned in the Qur'an and jurisprudence. But the Muslim's were killed