Al-Kāfi

Hadith 1765
8ـ أَحْمَدُ بْنُ مُحَمَّدٍ الْعَاصِمِيُّ عَنْ عَلِيِّ بْنِ الْحَسَنِ التَّيْمُلِيِّ عَنْ عَمْرِو بْنِ عُثْمَانَ الأَزْدِيِّ عَنْ مُحَمَّدِ بْنِ عُذَافِرٍ عَنْ عُمَرَ بْنِ يَزِيدَ قَالَ الرَّمَلُ فِي وَادِي مُحَسِّرٍ قَدْرُ مِائَةِ ذِرَاعٍ.
8. Ahmad ibn Muhammad al-’Asemiy has narrated from Ali ibn al-Husayn al-Taymuliy from ‘Amr ibn ‘Uthman al-Azdiy from Muhammad ibn ‘Adhafir from ‘Umar ibn Yazid who has said the following: “The distance to perform Sa‘y (running slowly) in Wadiy Muhassar is of one hundred yards.’”
Source: Shaykh Muḥammad b. Yaʿqūb al-Kulaynī