Maarif-ul-Quran
25:60 - 25:60

قَالُوا وَمَا الرَّ‌حْمَـٰنُ (60) The word رَّ‌حْمَـٰنُ (Rahman, translated as All-Merciful) is an Arabic word and all Arabs knew its meaning, but they did not use it for Allah Ta’ ala. Hence they enquired who and what is Rahman (رَّ‌حْمَـٰنُ ).