Sahih Muslim Book 26, Hadith 18
The expiation of the (breach of) a vow is the same as that of the (breach of an oath).
This hadith has been narrated on the authority of 'Uqba b. Amir Juhani. but in this no mention has been made of" barefoot".
Allah, the Great and Majestic, forbids you to swear by your fathers. Umar said: By Allah. I have never sworn (by my father) since I heard Allah's Messenger (ﷺ) forbidding it mentioning them" on my behalf" nor on behalf of someone else.