He wants to give up smoking; can he swear an oath concerning himself?

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Check below answers in case you are looking for other related questions:
He swore to name his son after his friend, but he wants to change his mind
He said to his wife: “You are to me like my mother”

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Related Answers:
She said to her husband: “You are to me like my father”
Is it mustahabb to observe fasts in expiation for breaking an oath as the six days of Shawwaal?
Vows do not change qadaa’ (divine decree)
He swore to name his son after his friend, but he wants to change his mind
He said to his wife: “You are to me like my mother”

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