Is the obligation of prayer immediate upon the entry of its time?
Chapter on Prayer Times
Al-Mughni
Book of Prayer
Primary text
The obligation for prayer is immediate upon the entry of its specified time. This is established by the command to perform the prayer at the appointed time, which implies immediate obligation. Moreover, the obligatory prayer requires the intention (Niyyah) of the prescribed prayer; if it were not immediately obligatory, it could be performed validly without the intention necessary for an obligation, similar to a voluntary prayer. This differs from a voluntary prayer, which does not require such intention and can be abandoned without resolving to perform it. Delaying the obligatory prayer is only permissible with the firm intention to perform it later, similar to delaying Maghrib on the night of Muzdalifah or delaying other prayers due to being engaged in fulfilling one of their prerequisites.
Supporting text
Abu Hanifa permits delaying the prayer if the remaining time is insufficient for performing more than one prayer, based on the premise that at the beginning of the time, the worshipper has the choice to perform or omit it, making it non-immediately obligatory like a voluntary prayer.