Narrated by Ahmad through Ibn Lahīʿah.

He also mentioned that some narrators said, “In five days,” while most reported seven. Thus, in their judgment, the sound version of the hadith of ʿAbdullāh ibn ʿAmr is that the Prophet, may Allah bless him and grant him peace, ultimately set seven days for him, having initially instructed him to recite it in a month. He therefore set the range between a month and a week. It has also been reported that he initially instructed him to recite it in forty days. This represents the more lenient end of the range, corresponding to three days at the more strenuous end.

As for the version which states:

“Whoever recites the Quran in fewer than three days does not understand it,”

this does not contradict the version specifying seven days. It is not an instruction addressed to ʿAbdullāh ibn ʿAmr, nor does it state that the Prophet made regularly reciting it in three days a prescribed sunnah. It merely states that whoever recites it in fewer than three days does not understand it. Its implication arises from the specified number, and this is a valid implication: the opposite judgment applies to someone who recites it in three days or more. Such opposition can consist in a difference even in only some respects.

Thus, if someone who occasionally recites it in three days may understand it, the intended meaning of the hadith is fulfilled. If doing so occasionally is prescribed for some people, it does not follow that maintaining this practice is recommended. Accordingly, no Companion during the Prophet’s lifetime is known to have maintained this practice—that is, to have regularly recited the Quran in fewer than seven days. For this reason, Imam Ahmad, may Allah have mercy on him, used to recite it once every seven days.