The commentators have differed over whether “descendants” in this verse refers to minors, adults, or both, holding three views. Their disagreement turns on whether the phrase “in faith” describes the descendants who follow or the believers whom they follow.

One group explained the meaning as follows: Those who believed, and whose descendants We caused to follow them in their faith, attaining faith like theirs—We will unite those descendants with them in rank. They said: This is supported by the reading, “and their descendants followed them,” which makes following an act performed by the descendants. They also said: Allah, glorified be He, has used “descendants” to refer to adults, as in His words: “And among his descendants were David and Solomon”; “Descendants of those We carried with Noah”; and “We were descendants after them. Will You then destroy us for what the followers of falsehood did?” These are the words of adults of sound understanding.

They said: This is also supported by what Sa‘īd ibn Jubayr narrated from Ibn ‘Abbās, tracing it back to the Prophet:

“Allah raises the believer’s descendants to his rank, even if their deeds fall short of his, so that they may bring him joy.”

This indicates that they entered Paradise through their deeds, but had no deeds sufficient to attain their fathers’ rank. He therefore raised them to that rank, although their deeds fell short of it. They further said: Faith consists of speech, deeds, and intention, and this is possible only for adults. On this understanding, the meaning is that Allah, glorified be He, gathers the believer’s descendants to him if they attain faith like his, for that is what truly following entails. Even if their faith is less than his, Allah raises them to his rank to bring him joy and complete his bliss. This is like the Prophet’s wives sharing his rank by virtue of their relationship to him, although they did not attain that rank through their deeds. May Allah bless him and grant him peace.

Another group said: “Descendants” here refers to minors. The meaning is: Those who believed, and whose descendants We caused to follow them by virtue of their fathers’ faith. Descendants follow their fathers, even while minors, in faith and its rulings concerning inheritance, blood money, funeral prayers for them, burial in Muslim cemeteries, and other matters, except for rulings specific to adults.

On this interpretation, the phrase “in faith” is grammatically in the accusative as a circumstantial qualifier of both objects; that is: We caused their descendants to follow them by virtue of the fathers’ faith.