Sa'd ibn Ubadah
Rumors of this one-sided renunciation of the pact spread and were confirmed by Muhammad's emissaries, Sa'd ibn Mua'dh and Sa'd ibn Ubadah, leading men of the Aws and Khazraj respectively. Sa'd ibn Mua'dh reportedly issued threats against the Qurayza but was restrained by his colleague. As this would have allowed the besiegers to access the city and thus meant the collapse of the defenders' strategy, Muhammad "became anxious about their conduct and sent some of the leading Muslims to talk to them; the result was disquieting." According to Ibn Ishaq, Muhammad sent Nuaym ibn Masud, a well-respected elder of the Ghatafan who had secretly converted to Islam, to go to Muhammad's enemies and sow discord among them. Nuaym went to the Qurayza and advised them to join the hostilities against Muhammad only if the besiegers provide hostages from among their chiefs. He then hurried to the invaders and warned them that if the Qurayza asked for hostages, it is because they intended to turn them over to the Medinan defenders. When the representatives of the Quraysh and the Ghatafan came to the Qurayza, asking for support in the planned decisive battle with Muhammad, the Qurayza indeed demanded hostages. The representatives of the besiegers refused, breaking down negotiations and resulting in the Banu Qurayza becoming extremely distrustful of the besieging army. The Qurayza did not take any actions to support them until the besieging forces retreated. Thus the threat of a second front against the defenders never materialised.