That the Messenger of Allah (ﷺ) said: "The atonement of a vow when it is not specified is the atonement of an oath."
Jami` at-Tirmidhi Book 20, Hadith 6
← Previous Hadith That the Prophet (ﷺ) said: "It is not for a person to vow about that over which he has no control."

Jami` at-Tirmidhi Book 20, Hadith 5 Next Hadith → That the Messenger of Allah (ﷺ) said: "O 'Abdur-Rahman! Do not ask for a position of leadership, for if you receive it due to asking, you will be left alone with it, and if you receive it without asking, then you will be aided in it. And if you take an oath and you see that something else is better than it, then do what is better, and make an atonement for your oath."

Jami` at-Tirmidhi Book 20, Hadith 7