What is the ruling on one who vowed not to do something and is unsure about the wording of his vow, whether it was to do or not to do, knowing that his intention was not to do it? And what is the ruling on one who vowed to disbelieve if he did something, then he did it, and is he considered a disbeliever until he expiates for his vow?

The questioner may be suffering from obsessive doubts, and should ignore them.

Whoever doubts the occurrence of a vow or the validity of its wording is not bound by anything, and the default is freedom from obligation.

If a person vows to abandon a specific sin: Scholars have differed on whether this vow is binding or not, and whether an expiation for breaking an oath is required if he violates it.

A vow to commit a sin is not permissible to undertake or fulfill by agreement, and what is obligatory in such a case is repentance and seeking forgiveness. Some scholars have gone further, stating that an expiation for breaking an oath is obligatory.

Intention is considered in a vow; so what matters is what the person intended, not what his tongue uttered unintentionally.

Whoever vows disbelief or ties it to an action, and then performs that action, is not considered a disbeliever unless he harbored disbelief in his heart or intended disbelief by that action.

Whoever owes an expiation and has not paid it, it remains a debt upon him until he pays it, but the acceptance of deeds does not depend on it.