Is expiation obligatory for one who broke his promise to Allah to abstain from backbiting, and then returned to it?

Backbiting is a major sin, and the Quran has forbidden it. The majority of scholars believe that a vow is not valid for an obligation, so there is no expiation for the questioner because she made a covenant with Allah to abandon something forbidden that must be abandoned.

However, Ibn Taymiyyah holds the view that expiation is obligatory, as when something made obligatory by religious law is vowed upon by a servant or a covenant is made with Allah concerning it, it then imposes a second obligation. Abandoning it would thus entail abandoning both the obligation by religious law and the obligation by the vow.

The questioner must repent to Allah for backbiting and breaking her promise.