even if they all fast on the same day.

This concession, however, applies only to fasts for which consecutive days are not stipulated. When consecutiveness is a condition—such as in an expiatory fast—it is impermissible for all the heirs to fast at the same time; instead, one of them fasts a portion of the required days and another completes the rest.

Scholarly disagreement
The jurists have held three different positions regarding making up the fasts owed by a deceased person:

1. Nothing is ever made up on his behalf, whether the obligation stemmed from a vow or from the Law itself. This is the view of the three imams.
2. Only a vowed fast is to be made up, not a fast originally required by the Law. This is the position of Imam Ahmad, al-Layth, Ishaq, Abu ʿUbayd, and was championed by Ibn al-Qayyim.
3. Both categories must be made up for the deceased: a vowed fast that he was able to perform but did not, and a fast inherently obligatory. This is the opinion of Abu Thawr and the hadith scholars; it was defended by Ibn Hazm and a number of Shafiʿi traditionists, while Imam al-Shafiʿi suspended his judgment on the authenticity of the relevant hadith.

Al-Bayhaqi said, “Had al-Shafiʿi reviewed all the transmission routes of these hadiths, he would, God willing, not have differed from them.” Shaykh ʿAbd al-Rahman al-Saʿdi also favored this view, stating that it was likewise the choice of Shaykh al-Islam with respect to every debt owed by the deceased—whether to Allah or to other human beings—regardless of whether he imposed it upon himself or it was imposed by the Law.

The opponents of making up such fasts cite several evidences:
• The Divine statement: “and that man will have nothing but what he strives for” (Q 53:39).
• The report from Ibn ʿAbbas: “No one may pray on behalf of another, nor may anyone fast on behalf of another” (narrated by al-Nasaʾi in al-Kubra 29181). A similar report is attributed to ʿAisha. Both companions narrated the hadiths permitting fasting for the deceased, yet they themselves interpreted the matter differently; their understanding therefore merits precedence, for they were more familiar with the hadith’s intent.

Those who unconditionally permit making up the fasts reason with the hadith under discussion, for it is general in