The word(s) "basic" appears 3 time(s) in 3 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) He it is Who has sent down to thee the Book: In it are verses basic or fundamental (of established meaning); they are the foundation of the Book: others are allegorical. But those in whose hearts is perversity follow the part thereof that is allegorical, seeking discord, and searching for its hidden meanings, but no one knows its hidden meanings except Allah. And those who are firmly grounded in knowledge say: "We believe in the Book; the whole of it is from our Lord:" and none will grasp the Message except men of understanding.

(2) A. L. R. (This is) a Book, with verses basic or fundamental (of established meaning), further explained in detail,- from One Who is Wise and Well-acquainted (with all things):

(3) Those who believe say, "Why is not a sura sent down (for us)?" But when a sura of basic or categorical meaning is revealed, and fighting is mentioned therein, thou wilt see those in whose hearts is a disease looking at thee with a look of one in swoon at the approach of death. But more fitting for them-