Does the obligatory vow become binding and doubly obligatory, such that a second obligation is added to the original obligation established by Sharīʿah, similar to what Imam Ibn Taymiyyah mentioned regarding the twofold obligation of obedience (by Allah's command and then by the ruler's command), and analogous to the covenant and pledge taken from the Children of Israel?

There is no need for distress, as the issue of vowing an obligatory act is a matter of scholarly disagreement, and a layperson follows whomever they trust among the people of knowledge. The majority of jurists (Hanafi, Maliki, Shafi'i, and the relied-upon opinion of the Hanbali schools) have agreed that vowing an obligatory act is not binding, because a vow is a commitment, and it is not valid to commit to something that is already obligatory. Some Hanbalis, like Sheikh Ibn Taymiyyah, are of the view that such a vow is binding and necessitates an expiation for breaking an oath if one abandons it. The matter is broad, so there is no blame on whoever acts according to the opinion of the majority, and this is the preferred view on our website.