Abdullah bin Abbas reported,

Saad bin Ubada asked the Messenger of Allah ﷺ for a ruling concerning a vow his mother had made which she had not fulfilled before she died. The Prophet ﷺ said, "Fulfill it on her behalf."

Tirmidhi 1546

Sahih

حدثنا قتيبة حدثنا الليث عن ابن شهاب عن عبيد الله بن عبد الله بن عتبة

عن ابن عباس

أن سعد بن عبادة استفتى رسول الله ﷺ في نذر كان على أمه توفيت قبل أن تقضيه فقال النبي ﷺ اقض عنها

الترمذي 1546صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami Tirmidhi
Book
Vows and oaths
Chapter
Fulfilling a vow on behalf of the deceased
Numbering
Darussalam 1546
Tirmidhi 1546