Messenger of Allah! to whom should I show kindness? He said: Your mother, your sister, your brother and the slave whom you set free and who is your relative, a due binding (on you), and a tie of relationship which should be joined.
Sunan Abi Dawud Book 43, Hadith 368
← Previous Hadith I said: Messenger of Allah! to whom should I show kindness? He replied: Your mother, next your mother, next your mother, and then comes your father, and then your relatives in order of relationship. The Messenger of Allah (ﷺ) said: If a man asks his slave whom he freed for giving him property which is surplus with him and he refuses to give it to him, the surplus property which he refused to give will be called on the Day of resurrection as a large bald snake.

Abu Dawud said: Aqra' means a snake whose hair of the head were removed on account of poison.

Sunan Abi Dawud Book 43, Hadith 367 Next Hadith → A man’s reviling of his parents is one of the grave sins. He was asked : Messenger of Allah! How does a man revile his parents? He replied: He reviles the father of a man who then reviles his father, and he reviles a man’s mother and he reviles his.

Sunan Abi Dawud Book 43, Hadith 369