(29) باب غَزْوَةُ الْخَنْدَقِ وَهْىَ الأَحْزَابُ
Narrated Anas:
Allah's Messenger (ﷺ) went out towards the Khandaq (i.e. Trench) and saw the Emigrants and the Ansar digging the trench in the cold morning. They had no slaves to do that (work) for them. When the Prophet saw their hardship and hunger, he said, '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."
Reference: Sahih al-Bukhari 4099
In-book reference: Book 64, Hadith 143
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 5, Book 59, Hadith 425