´It was narrated that Kathir bin Jumhan said:` "I saw Ibn Umar walking between As-Safa and Al-Marwah. He said: 'I am walking because I saw the Messenger of Allah Walking, and I hasten because I saw the Messenger of Allah hasten.'"
Hadith Referenceسنن نسائي / كتاب مناسك الحج / 2979
Kathir ibn Jamhan said: A man asked Abdullah ibn Umar between as-Safa and al-Marwah: Abdur Rahman, I see you walking while the people are running (between as-Safa and al-Marwah)? He replied: If I walk, I saw the Messenger of Allah ﷺ running. I am too old.
Shaykh Umar Farooq Saeedi
1904. Commentary: That is, one should perform sa‘i (running) between Safa and Marwah. However, if due to illness or severe old age one is unable to run, then walking will also suffice for him. And Allah knows best.
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 1904
´It was narrated that Ibn ‘Umar said:` “If I go quickly between Safa and Marwah, that is because I saw the Messenger of Allah (ﷺ) going quickly, and if I walk that is because I saw the Messenger of Allah (ﷺ) walking, even though I am an old man.”
Maulana Ataullah Sajid
Benefits and Issues: ➊ Running between the two green markers in the valley during the Sa’i (ritual walking) between Safa and Marwah is Sunnah.
➋ If a person is unable to run due to old age, illness, or weakness, then performing the Sa’i at a normal pace also fulfills the obligation.
➌ Ibn Umar (radi Allahu anhuma) mentioned his old age to clarify his excuse. This indicates that if there is no excuse, one should indeed run.
Source: Commentary on Sunan Ibn Mājah by Mawlānā ‘Atā’ullāh Sājid, Page: 2988