Narrated 'Uqba bin 'Aamir (RA):

Allah's Mssenger (ﷺ) said: "The atonement for a vow (Nadhr) is (the same as) the atonement an oath (Yamin)." [Reported by Muslim]. at-Tirmidhi added, "If he did not specify it." [And he graded it Sahih (authentic)].

وَعَنْ عُقْبَةَ بْنِ عَامِرٍ ‏- رضى الله عنه ‏- قَالَ: قَالَ رَسُولُ اَللَّهِ ‏- صلى الله عليه وسلم ‏-{

كَفَّارَةُ اَلنَّذْرِ كَفَّارَةُ يَمِينٍ

} رَوَاهُ مُسْلِمٌ.‏ [1]‏ .‏ وَزَادَ اَلتِّرْمِذِيُّ فِيهِ: { إِذَا لَمْ يُسَمِّ } , وَصَحَّحَهُ.‏ [2]‏ .‏