"Do not make vows, for a vow does not have any impact on the Qadar. Rather it is just a means of taking wealth from the miserly." (Using translation from Nasāʾī 3805)
قَالَ رَسُولُ اللهِ ﷺ لَا تَنْذِرُوا فَإِنَّالنَّذْرَ لَا يُقَدِّمُ مِنَ الْقَدَرِ شَيْئًا وَإِنَّمَا يُسْتَخْرَجُ بِهِ مِنَ الْبَخِيلِ