Sulaiman al-A'mash الأعمش / سليمان بن مهران · The Chapters on Expiation

the Messenger of Allah (ﷺ) said: "Whoever takes an oath, and swears, saying: 'By Al-Lat and Al-Uzza,' let him say:'La ilaha illallah.' "

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."

"Vows do not bring the son of Adam anything unless it has been decreed for him. But he is dominated by Divine preordainment, and will get what is decreed for him. And (vows) are a means of making the miser give something, so what he desires becomes obtainable for him, which was not obtainable before his vow. And Allah says: 'Spend, I will spend on you.'