Resting during السعي is جائز عند the consensus of scholars from all four schools of jurisprudence. A الحاج may sit down at الصفا, المروةh, or anywhere along the Mas'a corridor to rest, drink water, or recover from fatigue without invalidating their السعي. The continuity (muwalah) of السعي is مستحب (مستحب) but is not a condition (shart) for its validity عند جمهور العلماء.
الشيخ ابن عثيمين explicitly stated that taking breaks during السعي for rest, water, or to use the restroom is جائز, and the الحاج resumes from where they stopped. He noted that the Mas'a is a long corridor (approximately 450 meters each way), and performing seven complete laps is physically demanding, especially in the الحرارة. Islam does not impose unnecessary hardship, and resting is a natural and permitted response to fatigue.
If the iqamah for an واجب الصلاة is called during السعي, the الحاج should stop, join the congregational الصلاة, and then resume their السعي from the point where they stopped. الشيخ ابن باز confirmed this ruling, adding that resting on الصفا or المروةh to make دعاء (الدعاء) is actually from the السنة, as النبي used to make lengthy الأدعية while standing on الصفا and المروةh. The key point is that the الحاج must complete all seven laps — the breaks in between do not invalidate the previously completed laps.