´Narrated Ibn 'Abbas:` That Sa'd bin 'Ubadah asked the Messenger of Allah (ﷺ) about a vow that was due from his mother, who died before fulfilling it. The Prophet (ﷺ) said: "Fulfill it for her."
Hadith ReferenceSunan at-Tirmidhi / The Book on Vows and Oaths / Hadith: 1546