Sayyiduna Sahl bin Sa'd (may Allah be pleased with him) narrated that the Messenger of Allah (peace and blessings be upon him) came to us while we were digging the trench and carrying the earth on our shoulders, and the Messenger of Allah (peace and blessings be upon him) said: "True life is only the life of the Hereafter; O Allah, forgive the Muhajirun and the Ansar."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5854