In 5 AH the confederate tribes (al-Ahzab), led by Quraysh, besieged Madinah with a large coalition army. On the advice of Salman al-Farisi the Muslims dug a trench around the exposed side of the city, a defensive tactic unfamiliar to the Arabs. After a difficult siege, Allah sent a fierce cold wind and unseen forces that scattered the confederates without a decisive battle, and Surah al-Ahzab was revealed concerning it; the Prophet (صلى الله عليه وسلم) noted afterward that the initiative had now passed to the Muslims.
Evidence — the daleel
On deen2u
Informational, not a personal fatwa. Consult a qualified scholar for rulings on your situation.