The Prophet ﷺ said, "A slave is not bound by a vow concerning what he does not own."
حدثنا أحمد بن منيع حدثنا إسحق بن يوسف الأزرق عن هشام الدستوائي عن يحيى بن أبي كثير عن أبي قلابة
عن النبي ﷺ قال ليس على العبد نذر فيما لا يملك
Sourcing, agreed upon by Bukhari and Muslim. Muslim narrated it in the Book of Faith, chapter on the severity of the prohibition against a person killing himself, etc., hadith 110, from the hadith of Hisham Dastawai, and Bukhari, hadith 6047, from the hadith of Yahya bin Abu Kathir, with the same wording. On this subject there is also a narration from Abdullah bin Amr [mentioned previously, 1181] and from Imran bin Husayn [Muslim, hadith 1641].