Sunan al-Nasa'i — The Book of Oaths (qasamah), Retaliation and Blood Money

a man bit the hand of another man and his front tooth fell out. He came to the Prophet but he considered it in vain.

When the Messenger of Allah (ﷺ) swore an oath strongly, he said: No, by Him in Whose hand is the soul of AbulQasim.

the Messenger of Allah (ﷺ) was one of the best of men in character. One day he sent me to do something, and I said: I swore by Allah that I would not go. But in my heart I felt that I should go to do what the Prophet of Allah (ﷺ) had commanded me; so I went out and came upon some boys who were playing in the street. All of a sudden the Messenger of Allah (ﷺ) who had come up behind caught me by the back of the neck, and when I looked at him he was laughing. He said: Go where I ordered you, little Anas. I replied: Yes, I am going, Apostle of Allah! Anas said: I swear by Allah, I served him for seven or nine years, and he never said to me about a thing which I had done: Why did you do such and such? Nor about a thing which I left: why did not do such and such?

Do not hate each other; do not envy each other; do not desert each other; and be the servants of Allah as brethren. It is not allowed for a Muslim to keep apart from his brother for more than three days.

“The Messenger of Allah (ﷺ) pawned his armor to a jew in Al-Madinah, and took barely for his family in return.”