Sa`i is the devotional act of walking seven times back and forth between the two hills of Safa and Marwah. This act retraces the footsteps of Hajar (wife of Prophet Ibrahim) during her desperate search for water for her infant son Isma`il after they were left in the desert by Prophet Ibrahim (peace and blessings be upon him) in response to a divine vision.
Elaborating more on this, we cite what Sheikh Sayyed Sabiq states in his well-known book Fiqh As-Sunnah: Ibn `Abbas said: “Prophet Ibrahim (peace and blessings be upon him) brought Hajar, his wife, and her son Isma`il (peace and blessings be upon him), whom she was still nursing, and left them at (the site of) the House of Allah under a tree above the place where Zamzam emerged. At that time, Makkah was a barren place. There was neither water nor any people inhabiting it. He left a bag of dates and a container of water for them. Then Ibrahim (peace and blessings be upon him) turned to leave. Isma`il’s mother said to him, “O Ibrahim! Where are you going? And who are you leaving us to in this valley without anything or any companion?” She repeated this several times but he did not respond. At last she asked him, “Has Allah commanded you to do so?” He answered, “Yes.” Thereupon she said, “Then He will not let us perish!” (Al-Bukhari) In another narration we read: “She asked him, ‘Who are you leaving us to?’ He answered, ‘To Allah,’ whereupon she responded, ‘I am satisfied,’ and she turned back.
Ibrahim left and when he reached a mountain pass where he could no longer see them, he turned his face toward the Ka`bah and raised his hands in supplication, (O Our Lord! I have made my offspring to dwell in a valley without cultivation by Your Sacred House, in order Our Lord, that they may establish regular prayer: so, fill the hearts of some among men with love towards them, and feed them with fruits, so that they may give thanks!) (Ibrahim 14:37)
Hajar sat under the tree with her baby next to her. She drank from her water container, which was hanging nearby, and nursed her baby, until all the water she had was gone, and her milk dried up. Her son grew hungrier and hungrier, and she could hardly bear to look at him. She went and stood at Safa – the hill nearest to her. She looked down the valley to see if there was anyone around to help. She could see no one, so she climbed down Safa to the valley. She struggled hard, crossed the valley and reached Marwah. She stood at the top ofMount Marwah, and looked around. Still she could see no one around. She repeated this seven times. Ibn `Abbas added, “The Prophet (peace and blessings be upon him) said: ‘It is (to commemorate this walk) that pilgrims walk between Safa and Marwah.”‘