Sahih Muslim 1804
Sahih Muslim · Book 32: The Book of Jihad and Expeditions · The Battle of Al-Ahzab (The Confederates), also known as Al-Khandaq (The Ditch)
It has been reported on the authority of Sahl b. Sa'd who said:
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ الْقَعْنَبِيُّ ، حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ أَبِي حَازِمٍ ، عَنْ أَبِيهِ ، عَنْ سَهْلِ بْنِ سَعْدٍ ، قَالَ جَاءَنَا رَسُولُ اللَّهِ صلى الله عليه وسلم وَنَحْنُ نَحْفِرُ الْخَنْدَقَ وَنَنْقُلُ التُّرَابَ عَلَى أَكْتَافِنَا فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " اللَّهُمَّ لاَ عَيْشَ إِلاَّ عَيْشُ الآخِرَةِ فَاغْفِرْ لِلْمُهَاجِرِينَ وَالأَنْصَارِ " .
The Messenger of Allah (ﷺ) came to us while we were digging the ditch and were carrying the earth on our shoulders. (Seeing our condition), he said: O God, there is no life but the life of the Hereafter. So forgive Thou the Muhajirs and the Ansar.