Narrated Ibn 'Umar (RA):
The Prophet (ﷺ) forbade making vows, and said, "It does not bring good. Indeed, it is only a means by which something is extracted from the miserly."[Agreed upon]. (DE)
Reference (DE): Bulugh al-Maram 1384 (DE)
In-book reference (DE): Book 13, Hadith 11 (DE)
English translation (DE): Book 13, Hadith 1384 (DE)