"Whoever makes a vow and does not state it specifically, the expiation (for such a vow) is the expiation for breaking an oath. "  

قَالَ رَسُولُ اللَّهِ ﷺ مَنْ نَذَرَ نَذْرًا وَلَمْ يُسَمِّهِ فَكَفَّارَتُهُ كَفَّارَةُ يَمِينٍ  

"Whoever makes a vow and does not state it specifically, the expiation (for such a vow) is the expiation for breaking an oath. Whoever makes a vow and is not able to fulfill it, the expiation for that is the expiation for breaking an oath. Whoever makes a vow and is able to fulfill it, let him do so."  

عَنِ النَّبِيِّ ﷺ قَالَ مَنْ نَذَرَ نَذْرًا وَلَمْ يُسَمِّهِ فَكَفَّارَتُهُ كَفَّارَةُ يَمِينٍ وَمَنْ نَذَرَ نَذْرًا لَمْ يُطِقْهُ فَكَفَّارَتُهُ كَفَّارَةُ يَمِينٍ وَمَنْ نَذَرَ نَذْرًا أَطَاقَهُ فَلْيَفِ بِهِ  

"مَنْ نَذَرَ نَذْرًا وَلَمْ يُسَمِّهِ فَكَفَّارَتهُ كَفَّارَةُ يَمِينٍ".