Nuaym ibn Masud

Nuaym ibn Masud al-Ashja'i (died ca. 50 AH) was a Companion of the Prophet ﷺ famous for his role in the Battle of the Trench (Khandaq) in 5 AH / 627 CE, where he executed one of the most sophisticated intelligence operations in early Islamic history. He had been a close ally of the Quraysh and their tribal confederates, but he secretly embraced Islam just before the battle and came to the Prophet ﷺ offering to act as a covert agent.

The Prophet ﷺ accepted his offer, and Nuaym proceeded to sow distrust among the three parties threatening Medina — the Quraysh, the Ghatafan tribes, and the Banu Qurayza, who had broken their treaty with the Muslims. He told each group a different story calculated to make them demand pledges from the other parties before fighting, and each group's request for pledges convinced the others that betrayal was imminent. The confederation fell apart without delivering a decisive blow against Medina.

His deed at Khandaq is described in detail by Ibn Hisham, Ibn Kathir, and other seerah writers as a decisive intelligence victory. The Prophet ﷺ reportedly said that "war is deception" and praised the use of such stratagems in defense of the community. Nuaym's action is credited by historians as a major factor in the failure of the siege.

He went on to participate in subsequent campaigns and lived into the first decades of the caliphate. He died around 50 AH, remembered primarily for his singular act of strategic brilliance that helped preserve the early Muslim community at one of its most vulnerable moments.