Distance between East and West as sun's daily travel
Nahj al-Balāgha|Volume 1|Book 3|Chapter 294
٢٩٤. وَقَدْ سُئِلَ عَنْ مَسَافَةِ مَا بَيْنَ الْمَشْرِقِ وَالْمَغْرِبِ فَقَالَ (عليه السلام): مَسِيرَةُ يَوْمٍ لِلشَّمْسِ.
294. Amīr al-mu’minīn, peace be upon him, was asked about the distance between East and West when he replied: One day’s travelling for the sun.