Sayyiduna al-Bara' bin Azib (may Allah be pleased with him) said: I saw the Prophet (peace and blessings be upon him) on the day of the Trench; he (peace and blessings be upon him) was moving earth, and the dust was covering the hair of his (peace and blessings be upon him) chest, for he (peace and blessings be upon him) had a great deal of hair on his chest, and he was reciting the rajaz verses of Abdullah bin Rawahah (may Allah be pleased with him): 'Allahumma lawla anta mahtadayna
wa la tasaddaqna wa la sallayna
fa-anzilan sakinatan 'alayna
wa thabbitil-aqdama in laqayna
innal-a'da'a qad baghaw 'alayna
wa in aradu fitnatan abayna' "O Allah, were it not for You we would not have been guided, nor would we have given charity or prayed.
So send down tranquillity upon us, and make our feet firm when we meet (the enemy).
The enemies have transgressed against us; if they seek to cause tribulation, we refuse."
He would recite them in a loud voice. [Sahih. Bukhari: 2873. Muslim: 1083]
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13293