It is reported that he was the freedman-client of a woman from the Lakhm tribe; another view holds that his walāʾ was with the Umayyads. Though he walked with a limp, he was awe-inspiring, sharp in judgment, and resolute in action. He transmitted ḥadith from Tamim al-Dari, and those who narrated from him include his son ʿAbd al-ʿAziz and Yazid ibn Masruq.
Muʿāwiyah placed him in charge of the naval raids, so he campaigned against Cyprus (1) and built fortresses there. Over the furthest reaches of the Maghrib he appointed his freedman Ṭāriq, who hastened forward and conquered al-Andalus. Musa then followed, completed the conquest, and witnessed astonishing events. He fought a famous pitched battle with the Byzantines; when the Muslims were on the verge of breaking, Musa drew back the curtain of his pavilion, exposing his daughters and other womenfolk, stepped out, and raised his hands in tearful, humble supplication. The warriors smashed their sword-sheaths before him, fought with true resolve, victory descended, and they gained spoils beyond description—including the golden, jewel-studded Table of Solomon, peace be upon him.
It is also said that he seized sixteen sealed jars (2) bearing Solomon’s signet. He opened four of them and pierced one, whereupon a demon emerged, crying, “O Prophet of Allah, I shall never again sow corruption on earth.” The demon then looked about and said, “By Allah, I see neither Solomon nor his kingdom,” and departed; the remaining jars were reburied.
Al-Layth recounted that Musa sent his son Marwan at the head of an army, which returned with one hundred thousand captives. He also dispatched his nephew, who brought back another hundred thousand Berbers. A man guided him to a treasure in al-Andalus; when they removed its door, rubies and emeralds poured out in dazzling abundance. Al-Layth said, “Carpets were discovered woven with gold, pearls, and rubies, to such an extent that a person could not…"