The Prophet ﷺ forbade vowing and said, "In fact, vowing does not prevent anything, but it makes a miser to spend his property."  

نَهَى النَّبِيُّ ﷺ عَنِ النَّذْرِ قَالَ إِنَّهُ لاَ يَرُدُّ شَيْئًا وَإِنَّمَا يُسْتَخْرَجُ بِهِ مِنَ الْبَخِيلِ  

The Prophet ﷺ said, "Allah says, 'The vow, does not bring about for the son of Adam anything I have not decreed for him, but his vow may coincide with what has been decided for him, and by this way I cause a miser to spend of his wealth. So he gives Me (spends in charity) for the fulfillment of what has been decreed for him what he would not give Me before but for his vow."  

قَالَ النَّبِيُّ ﷺ لاَ يَأْتِي ابْنَ آدَمَ النَّذْرُ بِشَىْءٍ لَمْ يَكُنْ قُدِّرَ لَهُ وَلَكِنْ يُلْقِيهِ النَّذْرُ إِلَى الْقَدَرِ قَدْ قُدِّرَ لَهُ فَيَسْتَخْرِجُ اللَّهُ بِهِ مِنَ الْبَخِيلِ فَيُؤْتِي عَلَيْهِ مَا لَمْ يَكُنْ يُؤْتِي عَلَيْهِ مِنْ قَبْلُ