Is it permissible to offer expiation for absolute vows that were made to be fulfilled daily, knowing that the opinion adopted for expiation is incorrect, but confining its application to the past and not the future?

An absolute vow — one that is not contingent on the attainment of a blessing or the warding off of an affliction — is a vow of righteousness (Nadhar At-Tabarrur), and fulfilling it is obligatory; expiation does not suffice for it, based on the saying of the Prophet, peace and blessings be upon him: "Whoever vows to obey Allah, let him obey Him."