To keep the Muslims’ spirits high while working on the trench the Prophet PBUH raised his voice and said:
وَاللَّهِ لَوْلاَ اللَّهُ مَا اهْتَدَيْنَا وَلاَ تَصَدَّقْنَا وَلاَ صَلَّيْنَا فَأَنْزِلَنْ سَكِينَةً عَلَيْنَا وَثَبِّتِ الأَقْدَامَ إِنْ لاَقَيْنَا إِنَّ الأُلَى قَدْ بَغَوْا عَلَيْنَا إِذَا أَرَادُوا فِتْنَةً أَبَيْنَا
“By Allah, without Allah we would not have been guided, neither would we have given in charity, nor would we have prayed. So (O Allah), please send Sakina (i.e. calmness) upon us, and make our feet firm if we meet the enemy as the enemy have rebelled against us, and if they intended affliction”
The Prophet PBUH also said:
اللَّهُمَّ إِنَّ الْعَيْشَ عَيْشُ الآخِرَهْ فَاغْفِرْ لِلأَنْصَارِ وَالْمُهَاجِرَهْ ” فَقَالُوا مُجِيبِينَ لَهُ نَحْنُ الَّذِينَ بَايَعُوا مُحَمَّدَا عَلَى الْجِهَادِ مَا بَقِينَا أَبَدَا
‘O Allah! The real life is the life of the Hereafter, so please forgive Ansar and the Emigrants.” They said in reply to him, “We are those who have given the Pledge of allegiances to Muhammad for to observe Jihad as long as we live.”