Sa'i is walking briskly seven times between the hills of Safa and Marwah, starting at Safa and ending at Marwah, following tawaf. It commemorates Hajar, the wife of Ibrahim, running desperately between the two hills searching for water for her infant son Ismail after Ibrahim left them in the barren valley of Mecca by Allah's command. Her trust and effort were answered when the Zamzam spring burst forth at Ismail's feet.
The Quran affirms this rite directly: "Indeed, Safa and Marwah are among the symbols of Allah. So whoever makes Hajj to the House or performs Umrah, there is no blame upon him for walking between them" (2:158) — a verse revealed partly to reassure early Muslims who hesitated, since idols had stood on these hills during the pre-Islamic period. Today, markers indicate a short stretch where men are encouraged to jog lightly, recalling Hajar's urgency, while women walk throughout. Sa'i must follow a valid tawaf, requires seven full traversals, and stands as a lasting tribute to a mother's faith and perseverance.