The question of performing sa'i before tawaf is one of the issues where scholars have significant differences of opinion. The majority of scholars — the Maliki, Shafi'i, and the well-known Hanbali position — hold that tawaf must precede sa'i, and sa'i performed before tawaf is invalid and must be repeated after performing tawaf. Their evidence is that the Prophet (peace be upon him) performed tawaf before sa'i in all his pilgrimages, and he said: 'Take your rites from me,' establishing that his order is to be followed.
The Hanafi school takes a different position, holding that while performing tawaf before sa'i is the Sunnah and preferred order, sa'i performed before tawaf is valid, though it is contrary to the recommended practice. This is based on the hadith narrated on the Day of Sacrifice when a man came to the Prophet and said: 'I performed sa'i before tawaf,' and the Prophet replied: 'No harm' (la haraja), indicating that the order is not a strict condition.
Sheikh Ibn Taymiyyah supported the view that the order between tawaf and sa'i is recommended but not obligatory, citing the hadith about the Prophet's response on the Day of Sacrifice. Ibn Uthaymeen, while generally following the majority position, acknowledged that the hadith provides evidence for flexibility. He recommended following the established order (tawaf then sa'i) as the safe and clear practice, while acknowledging that some scholars validate the reversed order based on the explicit hadith.