It is narrated from Hazrat Bara bin Azib (may Allah be pleased with him) that an Ansari came to the Prophet Muhammad (peace and blessings be upon him) who was covered in iron (armor) and said, "O Messenger of Allah! Should I accept Islam first or participate in jihad first?" The Prophet Muhammad (peace and blessings be upon him) said, "Accept Islam first, then participate in jihad." So he did so, and was martyred in that jihad. The Prophet Muhammad (peace and blessings be upon him) said, "He did little action but received a great reward."