Out of Allah's grace towards His believing servants, He prescribed for them dispensations with which they can make up for the missed acts of worship - obligatory and voluntary. In this Hadīth, the Prophet (may Allah's peace and blessings be upon him) points out that "Whoever sleeps and fails to recite his hizb or part of it" at night, as established in another version narrated by An-Nasā’i: "Whoever sleeps and fails to recite his hizb at night" i.e., he is overcome by sleep or gets prevented from it by a valid reason, yet he had the intention to do it. Hizb: The portion to which a person commits himself as a habit that he engages in voluntarily, like recitation of the Qur'an, dhikr, and prayer. Allah, out of His grace, gives him plenty of time. So, if he "recites it between the Fajr prayer and the Zhuhr prayer" i.e., he makes up for it during this time, because this is a good length of time during which a person can compensate for what he has missed in the night. Also, this is probably intended to encourage him to do it, for this is a time connected to the latter part of the night without separation between them save for the Fajr prayer. As recompense, the full reward will be added to his record of deeds as if he has done it at its usual time. Here is a slight manifestation of Allah's gentleness towards His servant, who perpetuates a certain condition of goodness. If anything arises from him that changes this condition, Allah bestows His favor upon him and does not detract from his reward, as if he has done it by virtue of his good and sincere intention. In the Hadīth: Urging people to make up for the missed supererogatory worship, lest they may get used to abandoning any of the act of worship altogether if they miss it And in it: The legitimacy of adopting a regular portion of worship at night And in it: The legitimacy of making up for the regular portion of worship at night if it is missed due to sleep or some other excuse.