The word(s) "plain" appears 70 time(s) in 69 verse(s) in Quran in Abdullah Yusuf Ali translation.

(21) Then (Moses) threw his rod, and behold! it was a serpent, plain (for all to see)!

(22) So We sent (plagues) on them: Wholesale death, Locusts, Lice, Frogs, And Blood: Signs openly self-explained: but they were steeped in arrogance,- a people given to sin.

(23) And We ordained laws for him in the tablets in all matters, both commanding and explaining all things, (and said): "Take and hold these with firmness, and enjoin thy people to hold fast by the best in the precepts: soon shall I show you the homes of the wicked,- (How they lie desolate)."

(24) Thus do We explain the signs in detail; and perchance they may turn (unto Us).

(25) But (even so), if they repent, establish regular prayers, and practise regular charity,- they are your brethren in Faith: (thus) do We explain the Signs in detail, for those who understand.

(26) There is no blame on those who are infirm, or ill, or who find no resources to spend (on the cause), if they are sincere (in duty) to Allah and His Messenger: no ground (of complaint) can there be against such as do right: and Allah is Oft-forgiving, Most Merciful.

(27) The ground (of complaint) is against such as claim exemption while they are rich. They prefer to stay with the (women) who remain behind: Allah hath sealed their hearts; so they know not (What they miss).

(28) It is He Who made the sun to be a shining glory and the moon to be a light (of beauty), and measured out stages for her; that ye might know the number of years and the count (of time). Nowise did Allah create this but in truth and righteousness. (Thus) doth He explain His Signs in detail, for those who understand.

(29) The likeness of the life of the present is as the rain which We send down from the skies: by its mingling arises the produce of the earth- which provides food for men and animals: (It grows) till the earth is clad with its golden ornaments and is decked out (in beauty): the people to whom it belongs think they have all powers of disposal over it: There reaches it Our command by night or by day, and We make it like a harvest clean-mown, as if it had not flourished only the day before! thus do We explain the Signs in detail for those who reflect.

(30) 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):