[Machine] The Messenger of Allah ﷺ forbade making vows and said, "Indeed, it does not bring forth anything but extracts it from the miserly." And in another narration it is said, "but it is extracted from the miserly."  

نَهَى رَسُولُ اللهِ ﷺ عَنِ النَّذْرِ وَقَالَ إِنَّهُ لَا يَرُدُّ شَيْئًا إِنَّمَا يُسْتَخْرَجُ بِهِ مِنَ الشَّحِيحِ وَفِي رِوَايَةِ خَلَّادٍ وَلَكِنْ يُسْتَخْرَجُ بِهِ مِنَ الشَّحِيحِ  

The vow does not bring anything near to the son of Adam which Allah has not ordained for him, but (at times) the vow coincides with Destiny, and this is how something is extracted from the miserly person, which that miser was not willing to give. (Using translation from Muslim 1640c)   

أَنَّ النَّبِيَّ ﷺ قَالَ إِنَّ النَّذْرَ لَا يُقَرِّبُ مِنَ ابْنِ آدَمَ شَيْئًا لَمْ يَكُنِ اللهُ قَدَّرَهُ لَهُ وَلَكِنَّ النَّذْرَ يُوَافِقُ الْقَدَرَ فَيُخْرَجُ بِذَلِكَ مِنَ الْبَخِيلِ مَا لَمْ يَكُنِ الْبَخِيلُ يُرِيدُ أَنْ يُخْرِجَهُ