Because they were scrupulous about performing tawaf between them, as tawaf between them in the Jahiliyyah was practiced by some of the people of shirk and idols from among the Arabs, those among them who would make ihram for some of their idols, and they were scrupulous about performing tawaf between them. So Allah—Glorious and Exalted—made known to His Prophet, peace and blessings be upon him, and his ummah that there is no sin upon them in performing tawaf between them, as some of them had imagined.

Hazrat Urwah (may Allah have mercy on him) narrates that I recited this verse in the presence of Sayyidah Aisha (may Allah be pleased with her) «‏‏‏‏إِنَّ الصَّفَا وَالْمَرْوَةَ مِن شَعَائِرِ اللَّهِ» ‏‏‏‏ [ سورة البقرة: 108] "Indeed, Safa and Marwah are among the symbols of Allah." I said that if someone does not perform Sa'i between these two, I think there is no sin upon him. Sayyidah Aisha (may Allah be pleased with her) said, "My brother, you have said a very wrong thing. The real situation is that (in the time of ignorance) those who would enter into Ihram in the name of the idol Manat, which was located at the place called Mushallal, would perform Sa'i between Safa and Marwah. Then, when the era of Islam came, the Companions said, 'O Messenger of Allah, performing Sa'i between these two stones is among the practices of ignorance.' So this verse was revealed «‏‏‏‏إِنَّ الصَّفَا وَالْمَرْوَةَ مِن شَعَائِرِ اللَّهِ» ‏‏‏‏ [ سورة البقرة: 108] 'Indeed, Safa and Marwah are among the symbols of Allah.' Sayyidah Aisha (may Allah be pleased with her) says, therefore, the Messenger of Allah (peace and blessings be upon him) performed Sa'i between Safa and Marwah, thus this act became Sunnah. In another narration from a Companion, Allah Almighty said «‏‏‏‏فَمَن تَطَوَّعَ خَيْرًا» ‏‏‏‏ [ سورة البقرة: 184 ] 'So whoever does good willingly...' So the Messenger of Allah (peace and blessings be upon him) performed this good deed willingly and performed Sa'i. Imam Zuhri says that I narrated this hadith to Abu Bakr bin Abdur Rahman, so he said, 'This is the only knowledge.' I heard many scholars say that those who performed Sa'i between Safa and Marwah said to the Prophet (peace and blessings be upon him), 'O Messenger of Allah, we have been commanded to perform Tawaf of the Sacred House, but not commanded to perform Sa'i between Safa and Marwah.' So upon this, Allah Almighty revealed this verse «‏‏‏‏إِنَّ الصَّفَا وَالْمَرْوَةَ مِن شَعَائِرِ اللَّهِ» ‏‏‏‏ [ سورة البقرة: 108] 'Indeed, Safa and Marwah are among the symbols of Allah.' Therefore, in my opinion, this verse was revealed regarding both groups."