The Prophet (ﷺ) said: Do not swear by your fathers, or by your mothers, or by rivals to Allah; and swear by Allah only, and swear by Allah only when you are speaking the truth.
Sunan Abi Dawud Book 22, Hadith 7
← Previous Hadith The Messenger of Allah (ﷺ) as saying: If anyone swears on oath is the course which he says: "By al-Lat" he should say: There is no god but Allah, and that if anyone says to his friend: Come and let me play for money with you, he should give something in charity (sadaqah).

Sunan Abi Dawud Book 22, Hadith 6 Next Hadith → The Messenger of Allah (ﷺ) found 'Umar al-Khattab in a caravan while he was swearing by his father. So he said: Allah forbids you to swear by forefathers. If anyone swears, he must swear by Allah or keep silence.

Sunan Abi Dawud Book 22, Hadith 8