Muhammad bin Yahya bin Hiban محمد بن يحيى بن حبان · The Chapters on Expiation

the Messenger of Allah (ﷺ) heard him swearing by his father. The Messenger of Allah (ﷺ) said: 'Allah forbids you from making oaths by your forefathers." 'Umar said: I never took an oath by them (i.e., my forefathers) myself nor narrating such words from anyone else.”

the Messenger of Allah (ﷺ) said: 'Do not take oaths by idols nor by your forefathers. "

The Messenger of Allah (ﷺ) said: 'Whoever takes an oath to follow a religion other than Islam, telling a deliberate lie, he will be as he said.'"

the Messenger of Allah (ﷺ) said: "Whoever says: 'I have nothing to do with Islam,' if he is lying then he is as he said, and if he is telling the truth, his Islam will not be sound."

the Messenger of Allah (ﷺ), said: "Whoever swears an oath then sees that something else is better than it, let him do that which is better and offer expiation for what he swore about. "

"The Messenger of Allah (ﷺ) offered expiation of a Sa' of dates, and he enjoined the people to do likewise. Whoever does not have that (must give) half a Sa' of wheat."

"I made a vow during the Ignorance period and I asked the Prophet (ﷺ) (about it) after I became Muslim. He told me to fulfill my vow."

a woman came to the Messenger of Allah (ﷺ) and said: "My mother has died, and she had made a vow to fast, but she died before she could fulfill it. The Messenger of Allah (ﷺ) said: 'Let her guardian fast on her behalf ."