There was a black companion who was martyred who did not know how to make Salah, never paid Zakah, nor fasted Ramadan during the Madani era; this companion was known as Aslam Ar-Ra’i (RA).
According Al-Isabah compiled by ibn Hajar Al-Asqalani, Aslam was from Abyssinian lineage and was a shepherd for Jewish people at Ghazwah Khaybar. He came to the Prophet (SAWS) and accepted Islam. Without making a single prayer, he then joined those who fought at Khaybar and was martyred.
Upon hearing of Aslam’s martyrdom, the Prophet (SAWS) declared, “Surely he is with his wife, al-hur al-‘ayn.”