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 (that Allah said), "Vowing does not bring to the son of Adam anything I have not already written in his fate, but vowing is imposed on him by way of fore ordainment. Through vowing I make a miser spend of his wealth."  

عَنِ النَّبِيِّ ﷺ قَالَ لاَ يَأْتِي ابْنَ آدَمَ النَّذْرُ بِشَىْءٍ لَمْ يَكُنْ قَدْ قَدَّرْتُهُ وَلَكِنْ يُلْقِيهِ الْقَدَرُ وَقَدْ قَدَّرْتُهُ لَهُ أَسْتَخْرِجُ بِهِ مِنَ الْبَخِيلِ