The Messenger of Allah ﷺ as saying: The atonement for a vow is the same as for an oath. Abu Dawud said: This tradition has also been transmitted by 'Amr b. al-Harith from Ka'b b. 'Alqamah, from Ibn Shamasah on the authority of 'Uqbah. (Using translation from Abū Dāʾūd 3323)  

أَنَّ رَسُولَ اللهِ ﷺ قَالَ «كَفَّارَةُ النَّذْرِ كَفَّارَةُ الْيَمِينِ»