What is the ruling when a resident Imam appoints a traveler among those praying with him as a successor during Salat al-Khawf?
Chapter on the Traveler's Prayer
Al-Mughni
Book of Prayer
Primary text
If the Imam is a resident and appoints a traveler from among his congregation as a successor, the entire congregation must complete the prayer (Itmam). This is because the successor (Mustakhlaf), having followed a resident earlier, is now obligated to complete the prayer, effectively acting as a resident.
Supporting text
If the traveler appointed as successor had not yet joined the prayer with the resident Imam, and the appointment occurred before the first group departed, then the first group must complete the prayer due to following the resident Imam, while the Imam and the second group may shorten their prayer (Qasr). If the succession occurs after the second group has joined the resident Imam, then all must complete the prayer, but the successor himself retains the option to shorten his prayer because he did not follow a resident Imam during his own main congregation period.