ibn Umar · The Book on Vows and Oaths

That the Messenger of Allah (ﷺ) came across 'Umar while he was on his mount, and he was swearing by his father. So the Messenger of Allah (ﷺ) said: "Verily Allah prohibits you from swearing by your fathers. So let the one who swears, swear by Allah, or be silent."

That the Messenger of Allah (ﷺ) said: "Whoever among you swears, saying in his oath: 'By Al-Lat! By Al-'Uzza!' Then let him say 'La ilaha illa Allah' And whoever says: 'Come let me gamble with you!' Then let him give in charity."