Devarim 23:23

²³ וְכִי תֶחְדַּל לִנְדֹּר לֹא־יִהְיֶה בְךָ חֵטְא׃

Ni Alexander Payne

Verse 22. But if it has not been confirmed into deliberate intention, that is, if the mind is not fully resolved that it is right, it is not binding.